btrfs: fix typos in comments

Fix typos that have snuck in since the last round. Found by codespell.

Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c
index 5fafc5e..313d9d6 100644
--- a/fs/btrfs/locking.c
+++ b/fs/btrfs/locking.c
@@ -57,7 +57,7 @@ void btrfs_tree_read_lock(struct extent_buffer *eb)
 /*
  * Try-lock for read.
  *
- * Retrun 1 if the rwlock has been taken, 0 otherwise
+ * Return 1 if the rwlock has been taken, 0 otherwise
  */
 int btrfs_try_tree_read_lock(struct extent_buffer *eb)
 {
@@ -72,7 +72,7 @@ int btrfs_try_tree_read_lock(struct extent_buffer *eb)
 /*
  * Try-lock for write.
  *
- * Retrun 1 if the rwlock has been taken, 0 otherwise
+ * Return 1 if the rwlock has been taken, 0 otherwise
  */
 int btrfs_try_tree_write_lock(struct extent_buffer *eb)
 {