drm/i915/selftests: Fix comment typo

Fix the double `wait' typo in comment.
Signed-off-by: Jason Wang <wangborong@cdjrlc.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220716040520.31676-1-wangborong@cdjrlc.com

drivers/gpu/drm/i915/selftests/i915_request.c

@@ -971,7 +971,7 @@ static struct i915_vma *empty_batch(struct drm_i915_private *i915)
 	if (err)
 		goto err;
 
-	/* Force the wait wait now to avoid including it in the benchmark */
+	/* Force the wait now to avoid including it in the benchmark */
 	err = i915_vma_sync(vma);
 	if (err)
 		goto err_pin;