block: Update bs->open_flags earlier in bdrv_open_common()

We're only doing this immediately before opening the image, but
bs->open_flags is used earlier in the function. At the moment this is
not causing problems because none of the checked flags are modified by
update_flags_from_options(), but this will change when we introduce
the "read-only" option.

This patch calls update_flags_from_options() at the beginning of the
function, immediately after creating the QemuOpts.
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block.c

@@ -961,6 +961,8 @@ static int bdrv_open_common(BlockDriverState *bs, BdrvChild *file,
         goto fail_opts;
     }
 
+    update_flags_from_options(&bs->open_flags, opts);
+
     driver_name = qemu_opt_get(opts, "driver");
     drv = bdrv_find_format(driver_name);
     assert(drv != NULL);
@@ -1022,9 +1024,6 @@ static int bdrv_open_common(BlockDriverState *bs, BdrvChild *file,
     bs->drv = drv;
     bs->opaque = g_malloc0(drv->instance_size);
 
-    /* Apply cache mode options */
-    update_flags_from_options(&bs->open_flags, opts);
-
     /* Open the image, either directly or using a protocol */
     open_flags = bdrv_open_flags(bs, bs->open_flags);
     if (drv->bdrv_file_open) {