cifs: fix check of error return from is_path_accessable

This function will return 0 if everything went ok. Commit 9d002df
however added a block of code after the following check for
rc == -EREMOTE. With that change and when rc == 0, doing the
"goto mount_fail_check" here skips that code, leaving the tlink_tree
and master_tlink pointer unpopulated. That causes an oops later
in cifs_root_iget.

Reported-and-Tested-by: Robbert Kouprie <robbert@exx.nl>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/connect.c

@@ -2839,7 +2839,7 @@ cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,
 			goto mount_fail_check;
 		}
 		rc = is_path_accessible(xid, tcon, cifs_sb, full_path);
-		if (rc != -EREMOTE) {
+		if (rc != 0 && rc != -EREMOTE) {
 			kfree(full_path);
 			goto mount_fail_check;
 		}