udev: blacklist /dev/md

Do not mount /dev/md by default via udev, this resolved a problem with the sanity test failing due to seeing the error while attempting to mount /dev/md0

---
 meta/recipes-core/udev/files/mount.blacklist |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

index d3ebb17..7c7d938 100644
@@ -1,3 +1,4 @@
 /dev/loop
 /dev/ram
 /dev/mtdblock
+/dev/md

1.7.6.4