fix cppcheck finding

[chipitsine]

we need to address the following cppcheck finding

src/cpuset.c:21:11: error: Found an exit path from function with non-void return type that has missing return statement [missingReturn]
src/cpuset.c:36:11: error: Found an exit path from function with non-void return type that has missing return statement [missingReturn]
src/cpuset.c:100:1: error: Found an exit path from function with non-void return type that has missing return statement [missingReturn]
src/cpuset.c:124:1: error: Found an exit path from function with non-void return type that has missing return statement [missingReturn]
src/cpuset.c:152:1: error: Found an exit path from function with non-void return type that has missing return statement [missingReturn]
src/cpuset.c:163:1: error: Found an exit path from function with non-void return type that has missing return statement [missingReturn]