tests: remove shm files created by vpp on reset

Even though we don't use shm transport anymore, vpp still populates shm.
Add cleanup before running tests to avoid the nuisance of running out of
space on /dev/shm.

Type: fix
Fixes: eb506becd0
Signed-off-by: Klement Sekera <ksekera@cisco.com>
Change-Id: I2ef87e991223ee60892d56af1482025d91e77d46

test/Makefile

@@ -257,6 +257,7 @@ shell: test-dep
 
 .PHONY: reset
 reset:
+	@rm -f /dev/shm/vpp-unittest-*
 	@rm -rf /tmp/vpp-unittest-*
 	@rm -f /tmp/api_post_mortem.*
 	@rm -rf $(FAILED_DIR)