mwifiex: replace spin_lock_irqsave with spin_lock and fix warn_on

We see this WARN_ON during PCIe unload:
WARNING: at kernel/smp.c:382 smp_call_function_many+0x66/0x1e1()

This happens because we are doing PCI iounmap operations while
holding spinlock via spin_lock_irqsave(). Holding spinlock this
way causes disabling IRQs and hence PCI iounmap shows warning on
irqs_disabled() check.

Use non-irq variant of spin_lock i.e. spin_lock() instead.
Signed-off-by: Avinash Patil <patila@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/mwifiex/init.c

@@ -687,7 +687,6 @@ mwifiex_shutdown_drv(struct mwifiex_adapter *adapter)
 	int ret = -EINPROGRESS;
 	struct mwifiex_private *priv;
 	s32 i;
-	unsigned long flags;
 	struct sk_buff *skb;
 
 	/* mwifiex already shutdown */
@@ -722,7 +721,7 @@ mwifiex_shutdown_drv(struct mwifiex_adapter *adapter)
 		}
 	}
 
-	spin_lock_irqsave(&adapter->mwifiex_lock, flags);
+	spin_lock(&adapter->mwifiex_lock);
 
 	if (adapter->if_ops.data_complete) {
 		while ((skb = skb_dequeue(&adapter->usb_rx_data_q))) {
@@ -738,7 +737,7 @@ mwifiex_shutdown_drv(struct mwifiex_adapter *adapter)
 
 	mwifiex_adapter_cleanup(adapter);
 
-	spin_unlock_irqrestore(&adapter->mwifiex_lock, flags);
+	spin_unlock(&adapter->mwifiex_lock);
 
 	/* Notify completion */
 	ret = mwifiex_shutdown_fw_complete(adapter);