block: Add missing bdrv_delete() for SG_IO BlockDriver in find_image_format() This patch adds a missing bdrv_delete() call in find_image_format() so that a SG_IO BlockDriver properly releases the temporary BlockDriverState *bs created from bdrv_file_open() Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org> Reported-by: Chris Krumme <chris.krumme@windriver.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>