ls: fix segfault-if-standalone-shell, add big fat comment.

coreutils/ls.c

@@ -777,6 +777,9 @@ static const unsigned opt_flags[] = {
 };
 
 
+/* THIS IS A "SAFE" APPLET, main() MAY BE CALLED INTERNALLY FROM SHELL */
+/* BE CAREFUL! */
+
 int ls_main(int argc, char **argv);
 int ls_main(int argc, char **argv)
 {
@@ -797,8 +800,6 @@ int ls_main(int argc, char **argv)
 	USE_FEATURE_AUTOWIDTH(char *terminal_width_str = NULL;)
 	USE_FEATURE_LS_COLOR(char *color_opt;)
 
-	setvbuf(stdout, bb_common_bufsiz1, _IOFBF, BUFSIZ);
-
 #if ENABLE_FEATURE_LS_TIMESTAMPS
 	time(&current_time_t);
 #endif