drm/i915/selftests: Careful not to flush hang_fini on error setups

Smatch spotted that we test at the start of hang_fini for a valid (h->gt
is only set after a request is created) but then used it regardless
later on.

v2: Alternatively, we do not need to check as we now always prime h->gt
in hang_init()

References: cb823ed9 ("drm/i915/gt: Use intel_gt as the primary object for handling resets")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190729085944.2179-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gt/selftest_hangcheck.c

@@ -272,9 +272,7 @@ static u32 hws_seqno(const struct hang *h, const struct i915_request *rq)
 static void hang_fini(struct hang *h)
 {
 	*h->batch = MI_BATCH_BUFFER_END;
-
-	if (h->gt)
-		intel_gt_chipset_flush(h->gt);
+	intel_gt_chipset_flush(h->gt);
 
 	i915_gem_object_unpin_map(h->obj);
 	i915_gem_object_put(h->obj);