vmdk: Use bdrv_nb_sectors() where sectors, not bytes are wanted Instead of bdrv_getlength(). Commit 57322b7 did this all over block, but one more bdrv_getlength() has crept in since. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: BenoƮt Canet <benoit.canet@nodalink.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>