autotest_common: delete ceph_raw.img after test

Recent change of ceph_raw.img size from 10G to 4G breaks
tests on patches which are not rebased or which use
previous SPKD releases.

Change-Id: I9dd79756e3cc7949593cd1c16d4735542d1fb32d
Signed-off-by: Karol Latecki <karol.latecki@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/449469
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>

test/common/autotest_common.sh

@@ -489,6 +489,7 @@ function rbd_setup() {
 function rbd_cleanup() {
 	if hash ceph; then
 		$rootdir/scripts/ceph/stop.sh || true
+		rm -f /var/tmp/ceph_raw.img
 	fi
 }