ide: insert BUG_ON() into __ide_set_handler() (take 2)

Replace the check for hwgroup->handler and printk(KERN_CRIT, ...) at the start
of __ide_set_handler() with mere BUG_ON() while removing such from the caller,
ide_execute_command(). Fix up the code formatting, while at it...
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/ide-iops.c

@@ -786,11 +786,7 @@ static void __ide_set_handler (ide_drive_t *drive, ide_handler_t *handler,
 {
 	ide_hwgroup_t *hwgroup = HWGROUP(drive);
 
-	if (hwgroup->handler != NULL) {
-		printk(KERN_CRIT "%s: ide_set_handler: handler not null; "
-			"old=%p, new=%p\n",
-			drive->name, hwgroup->handler, handler);
-	}
+	BUG_ON(hwgroup->handler);
 	hwgroup->handler	= handler;
 	hwgroup->expiry		= expiry;
 	hwgroup->timer.expires	= jiffies + timeout;
@@ -827,11 +823,9 @@ void ide_execute_command(ide_drive_t *drive, u8 cmd, ide_handler_t *handler,
 			 unsigned timeout, ide_expiry_t *expiry)
 {
 	unsigned long flags;
-	ide_hwgroup_t *hwgroup = HWGROUP(drive);
 	ide_hwif_t *hwif = HWIF(drive);
 
 	spin_lock_irqsave(&ide_lock, flags);
-	BUG_ON(hwgroup->handler);
 	__ide_set_handler(drive, handler, timeout, expiry);
 	hwif->OUTBSYNC(drive, cmd, IDE_COMMAND_REG);
 	/*