btrfs: remove duplicate journal_info reset on failure to commit transaction

btrfs: remove duplicate journal_info reset on failure to commit transaction

If we get an error during the transaction commit path, we are resetting
current->journal_info to NULL twice - once in btrfs_commit_transaction()
right before calling cleanup_transaction() and then once again inside
cleanup_transaction(). Remove the instance in btrfs_commit_transaction().

Reviewed-by: Anand Jain <asj@kernel.org>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>