libceph: rename ceph_calc_pg_primary()

Rename ceph_calc_pg_primary() to ceph_pg_to_acting_primary() to
emphasise that it returns acting primary.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
diff --git a/fs/ceph/ioctl.c b/fs/ceph/ioctl.c
index cca7fff..1831ad6 100644
--- a/fs/ceph/ioctl.c
+++ b/fs/ceph/ioctl.c
@@ -221,7 +221,7 @@
 		return r;
 	}
 
-	dl.osd = ceph_calc_pg_primary(osdc->osdmap, pgid);
+	dl.osd = ceph_pg_to_acting_primary(osdc->osdmap, &pgid);
 	if (dl.osd >= 0) {
 		struct ceph_entity_addr *a =
 			ceph_osd_addr(osdc->osdmap, dl.osd);