gfs2: pass a folio to __gfs2_jdata_write_folio()

Remove a couple of folio->page conversions in the callers, and two calls
to compound_head() in the function itself.  Rename it from
__gfs2_jdata_writepage() to __gfs2_jdata_write_folio().

Link: https://lkml.kernel.org/r/20230612210141.730128-3-willy@infradead.org


Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>