test: shrink a bit

function                                             old     new   delta
test_main                                              5     434    +429
bb_test                                              473       -    -473
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 1/0 up/down: 429/-473)          Total: -44 bytes
   text    data     bss     dec     hex filename
 735073    3028   14408  752509   b7b7d busybox_old
 735029    3028   14408  752465   b7b51 busybox_unstripped

diff --git a/coreutils/test.c b/coreutils/test.c
index 3796e2c..5ca4672 100644
--- a/coreutils/test.c
+++ b/coreutils/test.c
@@ -155,7 +155,7 @@
 #endif
 
 /* Cannot eliminate these static data (do the G trick)
- * because of bb_test usage from other applets */
+ * because of test_main usage from other applets */
 static char **t_wp;
 static struct t_op const *t_wp_op;
 static gid_t *group_array;
@@ -179,7 +179,7 @@
 static int is_a_group_member(gid_t gid);
 static void initialize_group_array(void);
 
-int bb_test(int argc, char **argv)
+int test_main(int argc, char **argv)
 {
 	int res;
 	char *arg0;
@@ -188,21 +188,19 @@
 	arg0 = strrchr(argv[0], '/');
 	if (!arg0++) arg0 = argv[0];
 	if (arg0[0] == '[') {
+		--argc;
 		if (!arg0[1]) { /* "[" ? */
-			--argc;
 			if (NOT_LONE_CHAR(argv[argc], ']')) {
 				bb_error_msg("missing ]");
 				return 2;
 			}
-			argv[argc] = NULL;
-		} else if (LONE_CHAR(arg0+1, '[') == 0) { /* "[[" ? */
-			--argc;
+		} else { /* assuming "[[" */
 			if (strcmp(argv[argc], "]]") != 0) {
 				bb_error_msg("missing ]]");
 				return 2;
 			}
-			argv[argc] = NULL;
 		}
+		argv[argc] = NULL;
 	}
 
 	res = setjmp(leaving);
@@ -571,7 +569,7 @@
 	if (ngroups > 0) {
 		/* FIXME: ash tries so hard to not die on OOM,
 		 * and we spoil it with just one xrealloc here */
-		/* We realloc, because bb_test can be entered repeatedly by shell.
+		/* We realloc, because test_main can be entered repeatedly by shell.
 		 * Testcase (ash): 'while true; do test -x some_file; done'
 		 * and watch top. (some_file must have owner != you) */
 		group_array = xrealloc(group_array, ngroups * sizeof(gid_t));
@@ -601,12 +599,3 @@
 
 	return 0;
 }
-
-
-/* applet entry point */
-
-int test_main(int argc, char **argv);
-int test_main(int argc, char **argv)
-{
-	return bb_test(argc, argv);
-}
diff --git a/include/libbb.h b/include/libbb.h
index 9ca5653..b7b0657 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -653,7 +653,7 @@
 /* applets which are useful from another applets */
 int bb_cat(char** argv);
 int bb_echo(char** argv);
-int bb_test(int argc, char** argv);
+int test_main(int argc, char** argv);
 int kill_main(int argc, char **argv);
 #if ENABLE_ROUTE
 void bb_displayroutes(int noresolve, int netstatfmt);
diff --git a/shell/ash.c b/shell/ash.c
index 35eec42..b54f666 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -10985,7 +10985,7 @@
 static int
 testcmd(int argc, char **argv)
 {
-	return bb_test(argc, argv);
+	return test_main(argc, argv);
 }
 #endif