bsg-lib: add module.h include

Due to conflicts with the moduleh tree in linux-next, we
run into an include file mess. We really need export.h
in that tree, but if we add module.h locally then the
issue is easier to resolve.

Reported-by: Stephen Rothwell <[e-mail]>
Signed-off-by: Jens Axboe <[e-mail]>

block/bsg-lib.c

···
 #include <linux/delay.h>
 #include <linux/scatterlist.h>
 #include <linux/bsg-lib.h>
+#include <linux/module.h>
 #include <scsi/scsi_cmnd.h>
 
 /**