zram: rename __zram_bvec_read to zram_read_page

__zram_bvec_read doesn't get passed a bvec, but always read a whole page. 
Rename it to make the usage more clear.

Link: https://lkml.kernel.org/r/20230411171459.567614-10-hch@lst.deSigned-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/block/zram/zram_drv.c

@@ -1397,7 +1397,7 @@ static int zram_read_from_zspool(struct zram *zram, struct page *page,
 	return ret;
 }
 
-static int __zram_bvec_read(struct zram *zram, struct page *page, u32 index,
+static int zram_read_page(struct zram *zram, struct page *page, u32 index,
 			  struct bio *bio, bool partial_io)
 {
 	int ret;
@@ -1436,7 +1436,7 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
 			return -ENOMEM;
 	}
 
-	ret = __zram_bvec_read(zram, page, index, bio, is_partial_io(bvec));
+	ret = zram_read_page(zram, page, index, bio, is_partial_io(bvec));
 	if (unlikely(ret))
 		goto out;
 
@@ -1593,7 +1593,7 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec,
 		if (!page)
 			return -ENOMEM;
 
-		ret = __zram_bvec_read(zram, page, index, bio, true);
+		ret = zram_read_page(zram, page, index, bio, true);
 		if (ret)
 			goto out;