md: removing typedefs:  mdk_rdev_t -> struct md_rdev

The typedefs are just annoying. 'mdk' probably refers to 'md_k.h'
which used to be an include file that defined this thing.

Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 11b9566..6b234af 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -248,7 +248,7 @@
 	unsigned long ops_request;
 
 	struct bio *return_bi;
-	mdk_rdev_t *blocked_rdev;
+	struct md_rdev *blocked_rdev;
 	int handle_bad_blocks;
 };
 
@@ -344,7 +344,7 @@
 
 
 struct disk_info {
-	mdk_rdev_t	*rdev;
+	struct md_rdev	*rdev;
 };
 
 struct raid5_private_data {