Kconfig: remove comment about scsi_wait_scan module

This module has been removed in commit 6072609d
([SCSI] Remove scsi_wait_scan module), so this module is gone since 3.6.
Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/scsi/Kconfig

@@ -242,13 +242,6 @@ config SCSI_SCAN_ASYNC
 	  system continues booting, and even probe devices on different
 	  busses in parallel, leading to a significant speed-up.
 
-	  If you have built SCSI as modules, enabling this option can
-	  be a problem as the devices may not have been found by the
-	  time your system expects them to have been.  You can load the
-	  scsi_wait_scan module to ensure that all scans have completed.
-	  If you build your SCSI drivers into the kernel, then everything
-	  will work fine if you say Y here.
-
 	  You can override this choice by specifying "scsi_mod.scan=sync"
 	  or async on the kernel's command line.