diag: Proper update of user PD mdlog session variables

The patch updates global variables of mdlog session
for user PD during different scenarios.

CRs-Fixed: 2058648
Change-Id: I503caddf8e9d504649ee8d81115da60267a5f560
Signed-off-by: Manoj Prabhu B <bmanoj@codeaurora.org>