Verify validity of monitor API getter parameters
Verify validity of monitor API getter parameters

Validate parameters to avoid segmentation fault, that would be caused by usage
of the Cynara Monitor API on NULL pointers.

Change-Id: I8a72fd812e6c91805938c95c10616870dc6e17bc
Signed-off-by: Lukasz Wojciechowski <a2d89656bbb2a6e8a64a294f13639c7f6683f95e@partner.samsung.com>

Samsung/cynara,Samsung/cynara,Samsung/cynara