btrfs: raid56: open code rbio_stripe_page_index()

There is only one caller for that helper now, and we're definitely fine
to open-code it.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2022-04-01 19:23:25 +08:00 • committed by David Sterba
commit f77183dc1f