dmaengine: cppi41: Clean up pointless warnings

With patches "dmaengine: cppi41: Fix runtime PM timeouts with USB mass
storage", and "dmaengine: cppi41: Fix oops in cppi41_runtime_resume",
the pm_runtime_get/put() in cppi41_irq() is no longer needed. We now
guarantee that cppi41 is enabled when dma is in use.

We can still get pointless error -115 when musb is configured as a
usb peripheral. That's because we should now check for the state of
is_suspended instead.

Let's just remove the now useless code and replace it with a WARN().
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/cppi41.c

@@ -323,12 +323,12 @@ static irqreturn_t cppi41_irq(int irq, void *data)
 
 		while (val) {
 			u32 desc, len;
-			int error;
 
-			error = pm_runtime_get(cdd->ddev.dev);
-			if (error < 0)
-				dev_err(cdd->ddev.dev, "%s pm runtime get: %i\n",
-					__func__, error);
+			/*
+			 * This should never trigger, see the comments in
+			 * push_desc_queue()
+			 */
+			WARN_ON(cdd->is_suspended);
 
 			q_num = __fls(val);
 			val &= ~(1 << q_num);
@@ -349,9 +349,6 @@ static irqreturn_t cppi41_irq(int irq, void *data)
 			c->residue = pd_trans_len(c->desc->pd6) - len;
 			dma_cookie_complete(&c->txd);
 			dmaengine_desc_get_callback_invoke(&c->txd, NULL);
-
-			pm_runtime_mark_last_busy(cdd->ddev.dev);
-			pm_runtime_put_autosuspend(cdd->ddev.dev);
 		}
 	}
 	return IRQ_HANDLED;