PCI: pciehp: Reduce PCIe slot_ctrl to 16 bits

4283c70e ("PCI: pciehp: Make pcie_wait_cmd() self-contained") added
a cache of the most recent command written to the Slot Control register.
This register is only 16 bits wide, but the cache ("slot_ctrl") is 32 bits.

Reduce slot_ctrl to a u16 so it matches the register size.  No functional
change.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

drivers/pci/hotplug/pciehp.h

@@ -92,7 +92,7 @@ struct controller {
 	struct slot *slot;
 	wait_queue_head_t queue;	/* sleep & wake process */
 	u32 slot_cap;
-	u32 slot_ctrl;
+	u16 slot_ctrl;
 	struct timer_list poll_timer;
 	unsigned long cmd_started;	/* jiffies */
 	unsigned int cmd_busy:1;

drivers/pci/hotplug/pciehp_hpc.c

@@ -171,7 +171,7 @@ static void pcie_wait_cmd(struct controller *ctrl)
 	 * interrupts.
 	 */
 	if (!rc)
-		ctrl_info(ctrl, "Timeout on hotplug command %#010x (issued %u msec ago)\n",
+		ctrl_info(ctrl, "Timeout on hotplug command %#06x (issued %u msec ago)\n",
 			  ctrl->slot_ctrl,
 			  jiffies_to_msecs(now - ctrl->cmd_started));
 }