zram: fix zram_bvec_read duplicate dump failure message and stat accumulation

When zram decompress fails, the code unnecessarily dumps failure messages and
does stat accumulation in function zram_decompress_page(), this work is already
done in function zram_decompress_page, the patch skips the redundant work.
Signed-off-by: NWanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/zram/zram_drv.c

@@ -207,11 +207,8 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
 
 	ret = zram_decompress_page(zram, uncmem, index);
 	/* Should NEVER happen. Return bio error if it does. */
-	if (unlikely(ret != LZO_E_OK)) {
-		pr_err("Decompression failed! err=%d, page=%u\n", ret, index);
-		zram_stat64_inc(zram, &zram->stats.failed_reads);
+	if (unlikely(ret != LZO_E_OK))
 		goto out_cleanup;
-	}
 
 	if (is_partial_io(bvec))
 		memcpy(user_mem + bvec->bv_offset, uncmem + offset,