tools: tc-testing: valgrindPlugin

Run the command under test under valgrind.  Produce an extra set of
tap output for the memory check on each test.

Signed-off-by: Brenda J. Butler <bjb@mojatatu.com>
Acked-by: Lucas Bates <lucasb@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>