md: rename "mdk_personality" to "md_personality"

"mdk" doesn't mean anything any more.

Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 921e966..eea9379 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5591,7 +5591,7 @@
 	return ERR_PTR(-EINVAL);
 }
 
-static struct mdk_personality raid5_personality;
+static struct md_personality raid5_personality;
 
 static void *raid6_takeover(struct mddev *mddev)
 {
@@ -5640,7 +5640,7 @@
 }
 
 
-static struct mdk_personality raid6_personality =
+static struct md_personality raid6_personality =
 {
 	.name		= "raid6",
 	.level		= 6,
@@ -5662,7 +5662,7 @@
 	.quiesce	= raid5_quiesce,
 	.takeover	= raid6_takeover,
 };
-static struct mdk_personality raid5_personality =
+static struct md_personality raid5_personality =
 {
 	.name		= "raid5",
 	.level		= 5,
@@ -5685,7 +5685,7 @@
 	.takeover	= raid5_takeover,
 };
 
-static struct mdk_personality raid4_personality =
+static struct md_personality raid4_personality =
 {
 	.name		= "raid4",
 	.level		= 4,