btrfs: drop unused parameter from btrfs_release_path

parameter tree root it's not used since commit
5f39d397dfbe140a14edecd4e73c34ce23c4f9ee ("Btrfs: Create extent_buffer
interface for large blocksizes")

Signed-off-by: David Sterba <dsterba@suse.cz>
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 80eabe8..566bdf2 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -376,7 +376,7 @@
 
 		search_start = max(key.offset, start);
 		if (recow) {
-			btrfs_release_path(root, path);
+			btrfs_release_path(path);
 			continue;
 		}
 
@@ -393,7 +393,7 @@
 			ret = btrfs_duplicate_item(trans, root, path,
 						   &new_key);
 			if (ret == -EAGAIN) {
-				btrfs_release_path(root, path);
+				btrfs_release_path(path);
 				continue;
 			}
 			if (ret < 0)
@@ -516,7 +516,7 @@
 			del_nr = 0;
 			del_slot = 0;
 
-			btrfs_release_path(root, path);
+			btrfs_release_path(path);
 			continue;
 		}
 
@@ -681,7 +681,7 @@
 		new_key.offset = split;
 		ret = btrfs_duplicate_item(trans, root, path, &new_key);
 		if (ret == -EAGAIN) {
-			btrfs_release_path(root, path);
+			btrfs_release_path(path);
 			goto again;
 		}
 		BUG_ON(ret < 0);
@@ -721,7 +721,7 @@
 			     inode->i_ino, bytenr, orig_offset,
 			     &other_start, &other_end)) {
 		if (recow) {
-			btrfs_release_path(root, path);
+			btrfs_release_path(path);
 			goto again;
 		}
 		extent_end = other_end;
@@ -738,7 +738,7 @@
 			     inode->i_ino, bytenr, orig_offset,
 			     &other_start, &other_end)) {
 		if (recow) {
-			btrfs_release_path(root, path);
+			btrfs_release_path(path);
 			goto again;
 		}
 		key.offset = other_start;