vfs: atomic_open(): fix create mode usage

Don't mask S_ISREG off the create mode before passing to ->atomic_open().  Other
methods (->create, ->mknod) also get the complete file mode and filesystems
expect it.
Reported-by: Steve <steveamigauk@yahoo.co.uk>
Reported-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Richard W.M. Jones <rjones@redhat.com>

fs/namei.c

@@ -2414,7 +2414,7 @@ static int atomic_open(struct nameidata *nd, struct dentry *dentry,
 		goto out;
 	}
 
-	mode = op->mode & S_IALLUGO;
+	mode = op->mode;
 	if ((open_flag & O_CREAT) && !IS_POSIXACL(dir))
 		mode &= ~current_umask();