Fix incorrect behavior on using MojErrCheck and friends in functions
with boolean return type.

:Release Notes:
Fix implicit conversion from MojErrCode to boolean type in functions
which declared as boolean-return but use MojErrCheck inside.

:Detailed Notes:
DB8 uses its own mechanism for error flow processing. Function must return
MojErr, which represents error code. For error checking MojErrCheck and
friends macroses are used. These macroses inline some conditions
checking and return statement with error code. If the function does not
return the specified type that can cause loss of the error code and lead
to misinterpretation of execution result. Also some macroses for convient
return result processing provided.

:Testing Performed:
Standard DB8 tests perfomed.

:QA Notes:

:Issues Addressed:
[ANG-1582] [DB8] MojErrCheck and return values

Open-webOS-DCO-1.0-Signed-off-by: Andrii Motsok <andrii.motsok@lge.com>

Change-Id: Ida805db15600b8cb1406ad4b8682970bbfb7d8e5
Reviewed-on: https://g2g.palm.com/4713
Reviewed-by: DCO Verification
Reviewed-by: Oleksii Uratkin <oleksii.uratkin@lge.com>
Tested-by: Oleksii Uratkin <oleksii.uratkin@lge.com>