[PATCH] audit: fix kstrdup() error check

kstrdup() returns NULL on error.

Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/auditfilter.c

@@ -800,7 +800,7 @@ static inline int audit_dupe_selinux_field(struct audit_field *df,
 
 	/* our own copy of se_str */
 	se_str = kstrdup(sf->se_str, GFP_KERNEL);
-	if (unlikely(IS_ERR(se_str)))
+	if (unlikely(!se_str))
 		return -ENOMEM;
 	df->se_str = se_str;