feat(app/common): add macro to convert app ret value

This patch adds a macro that converts int values to unsigned long wit
suppressing Coverity report on potential integer underflow.

Signed-off-by: Mate Toth-Pal <mate.toth-pal@arm.com>
Change-Id: Iac4d541ec027c528f288bc0f131a0e3dbe528102
1 file changed