waitPidStop: reduce sleep time to 10ms

Kill is a fast syscall, so we can reduce the sleep time from 100ms to
10ms in hope to speed things up a bit.

[NO NEW TESTS NEEDED]

Signed-off-by: Valentin Rothberg <vrothberg@redhat.com>

libpod/oci_conmon_common.go

@@ -965,7 +965,7 @@ func waitPidStop(pid int, timeout time.Duration) error {
 				}
 				logrus.Errorf("Pinging PID %d with signal 0: %v", pid, err)
 			}
-			time.Sleep(100 * time.Millisecond)
+			time.Sleep(10 * time.Millisecond)
 		}
 	}
 }