cifs: Improve guard for excluding $LXDEV xattr

$LXDEV xattr is for storing block/char device's major and minor number.
Change guard which excludes storing $LXDEV xattr to explicitly filter
everything except block and char device. Current guard is opposite, which
is currently correct but is less-safe. This change is required for adding
support for creating WSL-style symlinks as symlinks also do not use
device's major and minor numbers.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: pali

fs/smb/client/reparse.c

@@ -378,8 +378,8 @@ static int wsl_set_xattrs(struct inode *inode, umode_t _mode,
 
 	memset(iov, 0, sizeof(*iov));
 
-	/* Exclude $LXDEV xattr for sockets and fifos */
-	if (S_ISSOCK(_mode) || S_ISFIFO(_mode))
+	/* Exclude $LXDEV xattr for non-device files */
+	if (!S_ISBLK(_mode) && !S_ISCHR(_mode))
 		num_xattrs = ARRAY_SIZE(xattrs) - 1;
 	else
 		num_xattrs = ARRAY_SIZE(xattrs);