drm/i915/selftest: Cope with not having an RCS engine

It is no longer guaranteed that there will always be an RCS engine.
So, use the helper function for finding the first available engine that
can be used for general purpose selftets.
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220728024225.2363663-5-John.C.Harrison@Intel.com

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

@@ -1302,13 +1302,15 @@ static int igt_reset_wait(void *arg)
 {
 	struct intel_gt *gt = arg;
 	struct i915_gpu_error *global = &gt->i915->gpu_error;
-	struct intel_engine_cs *engine = gt->engine[RCS0];
+	struct intel_engine_cs *engine;
 	struct i915_request *rq;
 	unsigned int reset_count;
 	struct hang h;
 	long timeout;
 	int err;
 
+	engine = intel_selftest_find_any_engine(gt);
+
 	if (!engine || !intel_engine_can_store_dword(engine))
 		return 0;
 
@@ -1432,7 +1434,7 @@ static int __igt_reset_evict_vma(struct intel_gt *gt,
 				 int (*fn)(void *),
 				 unsigned int flags)
 {
-	struct intel_engine_cs *engine = gt->engine[RCS0];
+	struct intel_engine_cs *engine;
 	struct drm_i915_gem_object *obj;
 	struct task_struct *tsk = NULL;
 	struct i915_request *rq;
@@ -1444,6 +1446,8 @@ static int __igt_reset_evict_vma(struct intel_gt *gt,
 	if (!gt->ggtt->num_fences && flags & EXEC_OBJECT_NEEDS_FENCE)
 		return 0;
 
+	engine = intel_selftest_find_any_engine(gt);
+
 	if (!engine || !intel_engine_can_store_dword(engine))
 		return 0;
 
@@ -1819,12 +1823,14 @@ static int igt_handle_error(void *arg)
 {
 	struct intel_gt *gt = arg;
 	struct i915_gpu_error *global = &gt->i915->gpu_error;
-	struct intel_engine_cs *engine = gt->engine[RCS0];
+	struct intel_engine_cs *engine;
 	struct hang h;
 	struct i915_request *rq;
 	struct i915_gpu_coredump *error;
 	int err;
 
+	engine = intel_selftest_find_any_engine(gt);
+
 	/* Check that we can issue a global GPU and engine reset */
 
 	if (!intel_has_reset_engine(gt))