cifs: missing null check for newinode pointer

in cifs_do_create we check if newinode is valid before referencing it
but are missing the check in one place in fs/cifs/dir.c

Addresses-Coverity: 1357292 ("Dereference after null check")
Acked-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/dir.c

@@ -384,6 +384,7 @@ cifs_create_set_dentry:
 		goto out_err;
 	}
 
+	if (newinode)
 		if (S_ISDIR(newinode->i_mode)) {
 			rc = -EISDIR;
 			goto out_err;