ide: remove IDE_ARCH_INTR (v2)

This micro-optimization is not worth it.  Just always check for
existence of ->ack_intr method in ide_intr() and ide_timer_expiry().

v2:
Fix brown-paper-bag bug spotted by David D. Kilzer.

Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michael Schmitz <schmitz@debian.org>
Cc: "David D. Kilzer" <ddkilzer@kilzer.net>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

arch/m68k/include/asm/ide.h

diff --git a/arch/m68k/include/asm/ide.h b/arch/m68k/include/asm/ide.h
index b996a3c..9f95f06 100644
--- a/arch/m68k/include/asm/ide.h
+++ b/arch/m68k/include/asm/ide.h
@@ -123,8 +123,5 @@
 }
 #endif /* CONFIG_BLK_DEV_FALCON_IDE */
 
-#define IDE_ARCH_ACK_INTR
-#define ide_ack_intr(hwif)	((hwif)->ack_intr ? (hwif)->ack_intr(hwif) : 1)
-
 #endif /* __KERNEL__ */
 #endif /* _M68K_IDE_H */

drivers/ide/ide-io.c

diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 2e92497..e850601 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -739,7 +739,8 @@
 		} else if (drive_is_ready(drive)) {
 			if (drive->waiting_for_dma)
 				hwif->dma_ops->dma_lost_irq(drive);
-			(void)ide_ack_intr(hwif);
+			if (hwif->ack_intr)
+				hwif->ack_intr(hwif);
 			printk(KERN_WARNING "%s: lost interrupt\n",
 				drive->name);
 			startstop = handler(drive);
@@ -854,7 +855,7 @@
 
 	spin_lock_irqsave(&hwif->lock, flags);
 
-	if (!ide_ack_intr(hwif))
+	if (hwif->ack_intr && hwif->ack_intr(hwif) == 0)
 		goto out;
 
 	handler = hwif->handler;

include/linux/ide.h

diff --git a/include/linux/ide.h b/include/linux/ide.h
index 9a38650..cda80b5 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -202,11 +202,6 @@
 
 #define MAX_HWIFS	10
 
-/* Currently only m68k, apus and m8xx need it */
-#ifndef IDE_ARCH_ACK_INTR
-# define ide_ack_intr(hwif) (1)
-#endif
-
 /* Currently only Atari needs it */
 #ifndef IDE_ARCH_LOCK
 # define ide_release_lock()			do {} while (0)