block: remove bvec_to_phys

We only use it in biovec_phys_mergeable and a m68k paravirt driver,
so just opencode it there.  Also remove the pointless unsigned long cast
for the offset in the opencoded instances.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/blk.h b/block/blk.h
index 8f7229b..50f74ce 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -157,8 +157,8 @@ static inline bool biovec_phys_mergeable(struct request_queue *q,
 		struct bio_vec *vec1, struct bio_vec *vec2)
 {
 	unsigned long mask = queue_segment_boundary(q);
-	phys_addr_t addr1 = bvec_to_phys(vec1);
-	phys_addr_t addr2 = bvec_to_phys(vec2);
+	phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset;
+	phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset;
 
 	if (addr1 + vec1->bv_len != addr2)
 		return false;