tests: basic/rpm.t leaves /var/tmp/rpm-tests.* directories

When the test is terminated early because nothing changed that requires
this test, the /var/tmp/rpm-tests.xxxxxx is not removed.

BUG: 963333
Change-Id: I98d44ca34f14d62da9d836c41a9015cfb520ff96
Signed-off-by: Kaleb S. KEITHLEY <kkeithle@redhat.com>
Reviewed-on: http://review.gluster.org/5015
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>