cleanup: node._try_shutdown does not pass expect_error to os_ops.kill (#297)

This argument (expect_error) it is a bad idea and should be removed from os_ops.kill

Author: dmitry-lipetsk

src/node.py

@@ -669,7 +669,7 @@ def _try_shutdown(self, max_attempts, with_force=False):
 
         try:
             eprint('Force stopping node {0} with PID {1}'.format(self.name, node_pid))
-            self.os_ops.kill(node_pid, signal.SIGKILL, expect_error=False)
+            self.os_ops.kill(node_pid, signal.SIGKILL)
         except Exception:
             # The node has already stopped
             pass