pata_sil680: make sil680_sff_exec_command() 'static'

... since, of course, it's not used outside this driver.

Signed-off-by: Sergei Shtylyov <[e-mail]>
Signed-off-by: Jeff Garzik <[e-mail]>

drivers/ata/pata_sil680.c

···
  *	LOCKING:
  *	spin_lock_irqsave(host lock)
  */
-void sil680_sff_exec_command(struct ata_port *ap,
-					const struct ata_taskfile *tf)
+static void sil680_sff_exec_command(struct ata_port *ap,
+				    const struct ata_taskfile *tf)
 {
 	DPRINTK("ata%u: cmd 0x%X\n", ap->print_id, tf->command);
 	iowrite8(tf->command, ap->ioaddr.command_addr);