memstick: r592: fix build warnings for !PM_SLEEP

When PM_SLEEP is not enabled, the r592_clear_interrupts() function is
never used.  If so, don't build it to prevent a compiler warning.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/memstick/host/r592.c

@@ -188,13 +188,15 @@ static void r592_host_reset(struct r592_device *dev)
 	r592_set_mode(dev, dev->parallel_mode);
 }
 
+#ifdef CONFIG_PM_SLEEP
 /* Disable all hardware interrupts */
 static void r592_clear_interrupts(struct r592_device *dev)
 {
 	/* Disable & ACK all interrupts */
 	r592_clear_reg_mask(dev, R592_REG_MSC, IRQ_ALL_ACK_MASK);
 	r592_clear_reg_mask(dev, R592_REG_MSC, IRQ_ALL_EN_MASK);
 }
+#endif
 
 /* Tests if there is an CRC error */
 static int r592_test_io_error(struct r592_device *dev)