quotaops: check setgid/setuid return code

setgid/setuid syscalls may fail for different reasons,
do not ignore these errors.

Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/quotaops.c b/quotaops.c
index 56cf622..5e6026e 100644
--- a/quotaops.c
+++ b/quotaops.c
@@ -218,8 +218,10 @@
 		int i;
 
 		sigprocmask(SIG_SETMASK, &omask, NULL);
-		setgid(getgid());
-		setuid(getuid());
+		if (setgid(getgid()))
+			die(1, _("%s failed: %s\n"), "setgid", strerror(errno));
+		if (setuid(getuid()))
+			die(1, _("%s failed: %s\n"), "setuid", strerror(errno));
 		if (!(ed = getenv("VISUAL")))
 			if (!(ed = getenv("EDITOR")))
 				ed = _PATH_VI;