stop passing nameidata to ->lookup()

Just the flags; only NFS cares even about that, but there are
legitimate uses for such argument.  And getting rid of that
completely would require splitting ->lookup() into a couple
of methods (at least), so let's leave that alone for now...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/hostfs/hostfs_kern.c

@@ -595,7 +595,7 @@ int hostfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 }
 
 struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry,
-			     struct nameidata *nd)
+			     unsigned int flags)
 {
 	struct inode *inode;
 	char *name;