sysdig module should be removed after test

Just like the lttng test, the sysdig_probe module should be removed after the test.

Otherwise the kernel security test will failed

  ======================================================================
  FAIL: test_140_kernel_modules_not_tainted (__main__.KernelSecurityTest)
  kernel modules are not marked with a taint flag (especially 'E' for TAINT_UNSIGNED_MODULE)
  ----------------------------------------------------------------------
  Traceback (most recent call last):
    File "./test-kernel-security.py", line 1572, in test_140_kernel_modules_not_tainted
      self.fail('Module \'%s\' is tainted: %s' % (fields[0], last_field))
  AssertionError: Module 'sysdig_probe' is tainted: (OE)

  ----------------------------------------------------------------------