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: Idcb3f97f5ec499ebb2da3ab6e1579128cad87c00
Signed-off-by: Ravi Aravamudhan <aravamud@codeaurora.org>