remove now-unneeded memset

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

loginutils/sulogin.c

@@ -51,9 +51,6 @@ int sulogin_main(int argc UNUSED_PARAM, char **argv)
 	/* Clear dangerous stuff, set PATH */
 	sanitize_env_if_suid();
 
-// bb_ask() already handles this
-//	signal(SIGALRM, catchalarm);
-
 	pwd = getpwuid(0);
 	if (!pwd) {
 		goto auth_error;