Replace index_in_[sub]str_array with index_in_[sub]strings,

which scans thru "abc\0def\0123\0\0" type strings. Saves 250 bytes.

   text    data     bss     dec     hex filename
 781266    1328   11844  794438   c1f46 busybox_old
 781010    1328   11844  794182   c1e46 busybox_unstripped

selinux/chcon.c

@@ -117,7 +117,7 @@ static const char chcon_longopts[] =
 	"range\0"          Required_argument "l"
 	"verbose\0"        No_argument       "v"
 	"reference\0"      Required_argument "\xff" /* no short option */
-	"\0";
+	;
 #endif
 
 int chcon_main(int argc, char **argv);