Fix ahci driver 'flags' type

The new type checking of the flags arguments to irqsave and friends
(commit 3f307891ce0e7b0438c432af1aacd656a092ff45) pointed out this thing
with a big nice warning.

Signed-off-by: Linus Torvalds <[e-mail]>

drivers/ata/ahci.c

···
 	void __iomem *mmio = ap->host->iomap[AHCI_PCI_BAR];
 	u32 em_ctl;
 	u32 message[] = {0, 0};
-	unsigned int flags;
+	unsigned long flags;
 	int pmp;
 	struct ahci_em_priv *emp;