btrfs: remove superfluous metadata check at btrfs_lookup_extent_info()

If we didn't found an extent item with the initial btrfs_search_slot()
call, it's pointless to test if the "metadata" variable is "true", because
right after we check if the key type is BTRFS_METADATA_ITEM_KEY and that
is the case only when "metadata" is set to "true". So remove the redundant
check.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/extent-tree.c

@@ -139,7 +139,7 @@ int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
 	if (ret < 0)
 		goto out_free;
 
-	if (ret > 0 && metadata && key.type == BTRFS_METADATA_ITEM_KEY) {
+	if (ret > 0 && key.type == BTRFS_METADATA_ITEM_KEY) {
 		if (path->slots[0]) {
 			path->slots[0]--;
 			btrfs_item_key_to_cpu(path->nodes[0], &key,