diag: Validate query dci event and log mask size properly

Currently there is possibility of out-of-bound read due to
incorrect validation of received dci event and log mask for
query. The patch update the validation for the same.

Change-Id: I4266eb0f69fdbfa48c5aacc17744dec83995e9e6
Signed-off-by: Hardik Arya <harya@codeaurora.org>