Do not hand k8s an ssh-backed verifier it must never use

Audited every ssh_obj call on the lblk path. All of them are either behind a
k8s branch, inside a docker-only mixin, or pure bookkeeping
(notify_outage_started only resets an in-memory clock). One was not: _init_lblk
built a RawDeviceVerifier over ssh_obj on both platforms.

On k8s it was inert -- _provision_raw replaces it with the pod-backed runner,
and _lblk_devices is empty until then, so nothing called it. But an ssh-backed
verifier sitting on a k8s object is an invitation for the next change to use it
and hang until the ssh timeout, which is exactly how this path produced

  Exception: All usernames failed for 10.0.0.10. Last error: timed out

None on k8s makes the mistake impossible rather than merely unlikely.

Author: RaunakJalan

e2e/e2e_tests/lblk/test_lblk.py

@@ -126,7 +126,14 @@ def _spdk_runner(self):
         return self.ssh_obj
 
     def _init_lblk(self):
-        self._verifier = RawDeviceVerifier(self.ssh_obj, self.logger)
+        # Docker's verifier reaches a client machine over ssh. K8s has no
+        # ssh-reachable target at all, so it gets no verifier here --
+        # _provision_raw builds one over _PodDeviceRunner once the block pod
+        # exists. Left as None rather than an ssh-backed one that happens to be
+        # unused: an ssh verifier sitting on a k8s object is an invitation for
+        # the next change to call it and hang for a timeout.
+        self._verifier = (None if self.k8s_test
+                          else RawDeviceVerifier(self.ssh_obj, self.logger))
         self._lblk_devices = {}
         self._lblk_volumes = []
         self._k8s_raw_pods = []