qemu-img: Explicit number replaced by a constant

Signed-off-by: Yi Li <yili@winhong.com>
Message-Id: <20200819013607.32280-1-yili@winhong.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
diff --git a/qemu-img.c b/qemu-img.c
index 37365d0..1d8c5cd 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -1201,10 +1201,10 @@
         *pnum = 0;
         return 0;
     }
-    is_zero = buffer_is_zero(buf, 512);
+    is_zero = buffer_is_zero(buf, BDRV_SECTOR_SIZE);
     for(i = 1; i < n; i++) {
-        buf += 512;
-        if (is_zero != buffer_is_zero(buf, 512)) {
+        buf += BDRV_SECTOR_SIZE;
+        if (is_zero != buffer_is_zero(buf, BDRV_SECTOR_SIZE)) {
             break;
         }
     }
@@ -2513,8 +2513,8 @@
             }
         }
 
-        qemu_opt_set_number(opts, BLOCK_OPT_SIZE, s.total_sectors * 512,
-                            &error_abort);
+        qemu_opt_set_number(opts, BLOCK_OPT_SIZE,
+                            s.total_sectors * BDRV_SECTOR_SIZE, &error_abort);
         ret = add_old_style_options(out_fmt, opts, out_baseimg, NULL);
         if (ret < 0) {
             goto out;