rtlwifi: Remove unnecessary synchronize_irq() before free_irq()

Calling synchronize_irq() right before free_irq() is quite useless. On one
hand the IRQ can easily fire again before free_irq() is entered, on the
other hand free_irq() itself calls synchronize_irq() internally (in a race
condition free way), before any state associated with the IRQ is freed.

Patch was generated using the following semantic patch:
// <smpl>
@@
expression irq;
@@
-synchronize_irq(irq);
 free_irq(irq, ...);
// </smpl>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/realtek/rtlwifi/pci.c

@@ -2392,7 +2392,6 @@ void rtl_pci_disconnect(struct pci_dev *pdev)
 	rtlpriv->cfg->ops->deinit_sw_vars(hw);
 
 	if (rtlpci->irq_alloc) {
-		synchronize_irq(rtlpci->pdev->irq);
 		free_irq(rtlpci->pdev->irq, hw);
 		rtlpci->irq_alloc = 0;
 	}