btrfs: use GFP_KERNEL in btrfs_alloc_inode

This callback is called directly from VFS, no locks are held at the
allocation time.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/inode.c

@@ -9430,7 +9430,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
 	struct btrfs_inode *ei;
 	struct inode *inode;
 
-	ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
+	ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;