PCI: remove unnecessary volatile in PCIe hotplug struct controller

Proper memory barriers have been added to order accesses
to ->cmd_busy, so volatile declaration for cmd_busy can
be removed.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
index d17233a..e3a1e7e 100644
--- a/drivers/pci/hotplug/pciehp.h
+++ b/drivers/pci/hotplug/pciehp.h
@@ -97,7 +97,7 @@
 	u32 slot_cap;
 	u8 cap_base;
 	struct timer_list poll_timer;
-	volatile int cmd_busy;
+	int cmd_busy;
 	unsigned int no_cmd_complete:1;
 };