make testing check_proc not rely on bash

also grandparents make this test fail but is not a problem in real live.
NPTest->testCmd uses "sh -c" already, so there is no need to do that twice.

plugins/t/check_procs.t

@@ -26,13 +26,11 @@ $result = NPTest->testCmd( "./check_procs -w 100000 -c 100000 -s Z" );
 is( $result->return_code, 0, "Checking less than 100000 zombie processes" );
 like( $result->output, '/^PROCS OK: [0-9]+ process(es)? with /', "Output correct" );
 
-SKIP: {
-	skip "No bash available", 2 unless(system("which bash > /dev/null") == 0);
-	$result = NPTest->testCmd( "bash -c './check_procs -a '/sbin/init'; true'" );
-	is( $result->return_code, 0, "Parent process is ignored" );
-	like( $result->output, '/^PROCS OK: 1 process?/', "Output correct" );
+if(fork() == 0) { exec("sleep 7"); } # fork a test process
+$result = NPTest->testCmd( "./check_procs -a 'sleep 7'" );
+is( $result->return_code, 0, "Parent process is ignored" );
+like( $result->output, '/^PROCS OK: 1 process?/', "Output correct" );
 
-}
 $result = NPTest->testCmd( "./check_procs -w 0 -c 100000" );
 is( $result->return_code, 1, "Checking warning if processes > 0" );
 like( $result->output, '/^PROCS WARNING: [0-9]+ process(es)? | procs=[0-9]+;0;100000;0;$/', "Output correct" );