diag: Add debug prints in error cases

In some error cases, returning error code without printing
any message which makes debugging difficult. Add more
extensive debugging prints in error cases.

Change-Id: I1bc147c4420942ecda953ab512f639f6683e511d
CRs-Fixed: 495436
Signed-off-by: Mohit Aggarwal <maggarwa@codeaurora.org>
diag: Fix race condition in diagchar driver

diag driver maintains socket logging process in global driver
structure which is manipulated in switch_logging and in close
file_operation.
There is a possibility of race while clearing the socket logging
process in close operation and sending signal in switch_logging
operation. Adding lock to serialize the two operations.

CRs-Fixed: 495063
Change-Id: I0064509c9ace18a8ff40c5a744363546a9021612
Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>
Merge "diag: Fix race condition in diagchar driver"
Merge "diag: Add debug prints in error cases"
Merge remote-tracking branch 'caf/jb_2.5' into cm-10.1-aeroevan