fs/ntfs3: Add check for kmemdup

Since the kmemdup may return NULL pointer,
it should be better to add check for the return value
in order to avoid NULL pointer dereference.

Fixes: b46acd6a6a ("fs/ntfs3: Add NTFS journal")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

fs/ntfs3/fslog.c

@@ -4256,6 +4256,10 @@ check_attribute_names:
 	rec_len -= t32;
 
 	attr_names = kmemdup(Add2Ptr(lrh, t32), rec_len, GFP_NOFS);
+	if (!attr_names) {
+		err = -ENOMEM;
+		goto out;
+	}
 
 	lcb_put(lcb);
 	lcb = NULL;