[SCSI] Make scsi.h independent of the rest of the scsi includes

This allows it to compile and be used on the ps3 platform that wants
to use the #define values in scsi.h without actually having
CONFIG_SCSI set.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/block/cmd-filter.c b/block/cmd-filter.c
index 504b275..572bbc2 100644
--- a/block/cmd-filter.c
+++ b/block/cmd-filter.c
@@ -22,6 +22,7 @@
 #include <linux/spinlock.h>
 #include <linux/capability.h>
 #include <linux/bitops.h>
+#include <linux/blkdev.h>
 
 #include <scsi/scsi.h>
 #include <linux/cdrom.h>