dmaengine: hsu: refactor hsu_dma_do_irq() to return int

Since we have nice macro IRQ_RETVAL() we would use it to convert a flag of
handled interrupt from int to irqreturn_t.

The rationale of doing this is:
a) hence we implicitly mark hsu_dma_do_irq() as an auxiliary function that
   can't be used as interrupt handler directly, and
b) to be in align with serial driver which is using serial8250_handle_irq()
   that returns plain int by design.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/dma/hsu.h b/include/linux/dma/hsu.h
index aaff68e..197eec6 100644
--- a/include/linux/dma/hsu.h
+++ b/include/linux/dma/hsu.h
@@ -41,8 +41,7 @@
 /* Export to the internal users */
 int hsu_dma_get_status(struct hsu_dma_chip *chip, unsigned short nr,
 		       u32 *status);
-irqreturn_t hsu_dma_do_irq(struct hsu_dma_chip *chip, unsigned short nr,
-			   u32 status);
+int hsu_dma_do_irq(struct hsu_dma_chip *chip, unsigned short nr, u32 status);
 
 /* Export to the platform drivers */
 int hsu_dma_probe(struct hsu_dma_chip *chip);
@@ -53,10 +52,10 @@
 {
 	return 0;
 }
-static inline irqreturn_t hsu_dma_do_irq(struct hsu_dma_chip *chip,
-					 unsigned short nr, u32 status)
+static inline int hsu_dma_do_irq(struct hsu_dma_chip *chip, unsigned short nr,
+				 u32 status)
 {
-	return IRQ_NONE;
+	return 0;
 }
 static inline int hsu_dma_probe(struct hsu_dma_chip *chip) { return -ENODEV; }
 static inline int hsu_dma_remove(struct hsu_dma_chip *chip) { return 0; }