ide: make wait_drive_not_busy() static again

After commit 7267c3377443322588cddaf457cf106839a60463 
wait_drive_not_busy() can become static again.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index 5eb6fa1..d320001 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -260,7 +260,7 @@
 	return ide_stopped;
 }
 
-u8 wait_drive_not_busy(ide_drive_t *drive)
+static u8 wait_drive_not_busy(ide_drive_t *drive)
 {
 	ide_hwif_t *hwif = HWIF(drive);
 	int retries;