Verify return value of the sigset manipulation functions to catch invalid signal numbers [1]. Use consistent style of not assigning the return value to a local variable.
Verify return value of the sigset manipulation functions
to catch invalid signal numbers [1]. Use consistent style of
not assigning the return value to a local variable.

Reported by:	Garrett Cooper <yanegomi gmail com> [1]
MFC after:	1 week

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase