diag: Add kmemleak_not_leak check to mark certain objects

Certain objects in the diag driver can be flagged falsely as
memory leaks. These objects will be freed when the driver exits.
This patch marks these objects as non-leaks.

Change-Id: I7c3ac8ac1fb9b54d8f1da62eed518669b7c663b0
Signed-off-by: Ravi Aravamudhan <aravamud@codeaurora.org>