[SCSI] fix scsi_wait_scan build problem

The #ifdef MODULE around the export of scsi_complete_async_scans()
which is the API the scsi_wait_scan module uses is incorrect and
causes the symbol to be undefined in certain circumstances leading to
a build failure.  Remove the defines.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/scsi_scan.c

@@ -181,10 +181,8 @@ int scsi_complete_async_scans(void)
 	return 0;
 }
 
-#ifdef MODULE
 /* Only exported for the benefit of scsi_wait_scan */
 EXPORT_SYMBOL_GPL(scsi_complete_async_scans);
-#endif
 
 /**
  * scsi_unlock_floptical - unlock device via a special MODE SENSE command