Btrfs: remove always true if branch in btrfs_get_extent

@path is always NULL when it comes to the if branch.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/inode.c

@@ -6821,19 +6821,15 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
 	em->len = (u64)-1;
 	em->block_len = (u64)-1;
 
+	path = btrfs_alloc_path();
 	if (!path) {
-		path = btrfs_alloc_path();
-		if (!path) {
-			err = -ENOMEM;
-			goto out;
-		}
-		/*
-		 * Chances are we'll be called again, so go ahead and do
-		 * readahead
-		 */
-		path->reada = READA_FORWARD;
+		err = -ENOMEM;
+		goto out;
 	}
 
+	/* Chances are we'll be called again, so go ahead and do readahead */
+	path->reada = READA_FORWARD;
+
 	ret = btrfs_lookup_file_extent(NULL, root, path, objectid, start, 0);
 	if (ret < 0) {
 		err = ret;