libbb: introduce and use xrealloc_vector

function                                             old     new   delta
xrealloc_vector_helper                                 -      51     +51
create_list                                           84      99     +15
getopt_main                                          690     695      +5
passwd_main                                         1049    1053      +4
get_cached                                            85      89      +4
msh_main                                            1377    1380      +3
add_match                                             42      41      -1
read_lines                                           720     718      -2
grave                                               1068    1066      -2
fill_match_lines                                     143     141      -2
add_to_dirlist                                        67      65      -2
add_input_file                                        49      47      -2
act                                                  252     250      -2
fsck_main                                           2252    2246      -6
man_main                                             765     757      -8
bb_internal_initgroups                               228     220      -8
cut_main                                            1052    1041     -11
add_edge_to_node                                      55      43     -12
dpkg_main                                           3851    3835     -16
ifupdown_main                                       2202    2178     -24
sort_main                                            838     812     -26
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 5/15 up/down: 82/-124)          Total: -42 bytes

diff --git a/libbb/get_line_from_file.c b/libbb/get_line_from_file.c
index 66ea5a1..3a76f49 100644
--- a/libbb/get_line_from_file.c
+++ b/libbb/get_line_from_file.c
@@ -42,7 +42,7 @@
 		//	free(linebuf);
 		//	return NULL;
 		//}
-		linebuf = xrealloc(linebuf, idx+1);
+		linebuf = xrealloc(linebuf, idx + 1);
 		linebuf[idx] = '\0';
 	}
 	return linebuf;