diag: Fix wrongly marked kmemleak_not_leak

Current code does mark kmemleak_not_leak wrongly which leads
to issue of coloring unknown object. This patch fixes
this issue.

Change-Id: Ic03105cdb0208175a284f1900c4fe6e423fdf61e
Signed-off-by: Mohit Aggarwal <maggarwa@codeaurora.org>