*: shrink by using [f]open_or_warn_stdin where appropriate

function                                             old     new   delta
lsattr_main                                           62     143     +81
open_or_warn_stdin                                     -      36     +36
fclose_if_not_stdin                                   20      47     +27
xfopen_stdin                                           -      20     +20
tac_main                                             336     356     +20
cksum_main                                           249     259     +10
bb_argv_dash                                           -       8      +8
su_main                                              448     455      +7
cmp_main                                             630     633      +3
passwd_main                                         1072    1074      +2
uudecode_main                                        317     315      -2
text_yank                                            110     108      -2
handle_incoming_and_exit                            2653    2651      -2
flags                                                  5       1      -4
write_leases                                         235     230      -5
fopen_or_warn_stdin                                   48      42      -6
fold_main                                            648     642      -6
static.argv_dash                                       8       -      -8
sum_main                                             142     128     -14
tail_main                                           1237    1221     -16
sed_main                                             711     695     -16
cmp_xfopen_input                                      17       -     -17
bb_cat                                               113      96     -17
catv_main                                            328     306     -22
strings_main                                         457     434     -23
hash_file                                            298     274     -24
sum_file                                             353     325     -28
sort_main                                            904     859     -45
expand_main                                          736     686     -50
cut_main                                            1116    1065     -51
md5_sha1_sum_main                                    549     493     -56
lsattr_args                                           90       -     -90
read_stduu                                           408     255    -153
------------------------------------------------------------------------------
(add/remove: 3/3 grow/shrink: 7/20 up/down: 214/-657)        Total: -443 bytes
   text    data     bss     dec     hex filename
 797417     658    7428  805503   c4a7f busybox_old
 796973     658    7428  805059   c48c3 busybox_unstripped

diff --git a/coreutils/expand.c b/coreutils/expand.c
index c013395..a7ac8ea 100644
--- a/coreutils/expand.c
+++ b/coreutils/expand.c
@@ -154,7 +154,7 @@
 	if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e')) {
 		USE_FEATURE_EXPAND_LONG_OPTIONS(applet_long_options = expand_longopts);
 		opt = getopt32(argv, "it:", &opt_t);
-	} else if (ENABLE_UNEXPAND) {
+	} else {
 		USE_FEATURE_UNEXPAND_LONG_OPTIONS(applet_long_options = unexpand_longopts);
 		/* -t NUM sets also -a */
 		opt_complementary = "ta";
@@ -166,32 +166,23 @@
 
 	argv += optind;
 
-	/* If no args are given, read from stdin */
 	if (!*argv) {
 		*--argv = (char*)bb_msg_standard_input;
-		goto use_stdin;
 	}
-
 	do {
-		if (NOT_LONE_CHAR(*argv, '-')) {
-			file = fopen_or_warn(*argv, "r");
-			if (!file) {
-				exit_status = EXIT_FAILURE;
-				continue;
-			}
-		} else {
- use_stdin:
-			file = stdin;
+		file = fopen_or_warn_stdin(*argv);
+		if (!file) {
+			exit_status = EXIT_FAILURE;
+			continue;
 		}
 
 		if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e'))
 			USE_EXPAND(expand(file, tab_size, opt));
-		else if (ENABLE_UNEXPAND)
+		else
 			USE_UNEXPAND(unexpand(file, tab_size, opt));
 
 		/* Check and close the file */
-		/* We do want all of them to execute, thus | instead of || */
-		if (ferror(file) | fclose_if_not_stdin(file)) {
+		if (fclose_if_not_stdin(file)) {
 			bb_simple_perror_msg(*argv);
 			exit_status = EXIT_FAILURE;
 		}