btrfs: Call kunmap if zlib_inflateInit2 fails

If zlib_inflateInit2 fails, the input page is never unmapped.
Add a call to kunmap when it fails.

Signed-off-by: Nick Terrell <nickrterrell@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
1 file changed