md: rename "mdk_personality" to "md_personality"

"mdk" doesn't mean anything any more.

Signed-off-by: NeilBrown <neilb@suse.de>

diff --cc drivers/md/faulty.c
Simple merge

diff --cc drivers/md/linear.c
Simple merge

diff --cc drivers/md/md.c
Simple merge

diff --cc drivers/md/md.h
Simple merge

diff --cc drivers/md/multipath.c
Simple merge

diff --cc drivers/md/raid0.c
Simple merge

diff --cc drivers/md/raid1.c
Simple merge

diff --cc drivers/md/raid10.c
Simple merge

diff --cc drivers/md/raid5.c
Simple merge