zram: use memcpy_to_bvec in zram_bvec_read

Use the proper helper instead of open coding the copy.

Signed-off-by: Christoph Hellwig <[e-mail]>
Reviewed-by: Ira Weiny <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jens Axboe <[e-mail]>

drivers/block/zram/zram_drv.c

···
 		goto out;
 
 	if (is_partial_io(bvec)) {
-		void *dst = kmap_atomic(bvec->bv_page);
 		void *src = kmap_atomic(page);
 
-		memcpy(dst + bvec->bv_offset, src + offset, bvec->bv_len);
+		memcpy_to_bvec(bvec, src + offset);
 		kunmap_atomic(src);
-		kunmap_atomic(dst);
 	}
 out:
 	if (is_partial_io(bvec))