tests: tracepoint_alias properly skip if no perf_event support
tests: check_schedulability -- skip if no perf_event support
tests: check_papi_multiplexing -- skip if no perf_event support
tests: context_switch_user_kernel -- update whitespace

thought it needed fixing but actually was running correctly
tests: max_multiplex -- properly skip if no perf_event support
tests: signal_after_exec -- clean up whitespace

ugly output if no perf_event support but maybe not worth fixing