[SCSI] make scsi_wait_scan always modular

Currently scsi_wait_scan is only built modular if SCSI is modular.
However, it's perfectly possible for a built in SCSI still to have
modular drivers and thus need scsi_wait_scan as a module.  Therefore,
scsi_wait_scan should always be built as a module (unless the kernel
doesn't support modules).
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/Kconfig

@@ -241,6 +241,12 @@ config SCSI_SCAN_ASYNC
 	  You can override this choice by specifying "scsi_mod.scan=sync"
 	  or async on the kernel's command line.
 
+config SCSI_WAIT_SCAN
+	tristate
+	default m
+	depends on SCSI
+	depends on MODULES
+
 menu "SCSI Transports"
 	depends on SCSI
 

drivers/scsi/Makefile

@@ -145,7 +145,7 @@ obj-$(CONFIG_CHR_DEV_SCH)	+= ch.o
 # This goes last, so that "real" scsi devices probe earlier
 obj-$(CONFIG_SCSI_DEBUG)	+= scsi_debug.o
 
-obj-$(CONFIG_SCSI)		+= scsi_wait_scan.o
+obj-$(CONFIG_SCSI_WAIT_SCAN)	+= scsi_wait_scan.o
 
 scsi_mod-y			+= scsi.o hosts.o scsi_ioctl.o constants.o \
 				   scsicam.o scsi_error.o scsi_lib.o \