Revert wrong fixes for common misspellings

These changes were incorrectly fixed by codespell. They were now
manually corrected.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 2e61fe1..8f4b81d 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -718,7 +718,7 @@
 	u64 total_bytes;	/* total bytes in the space,
 				   this doesn't take mirrors into account */
 	u64 bytes_used;		/* total bytes used,
-				   this does't take mirrors into account */
+				   this doesn't take mirrors into account */
 	u64 bytes_pinned;	/* total bytes pinned, will be freed when the
 				   transaction finishes */
 	u64 bytes_reserved;	/* total bytes the allocator has reserved for