[PATCH] sysctl: md: remove unnecessary insert_at_head flag

The sysctls used by the md driver are have unique binary numbers so remove the
insert_at_head flag as it serves no useful purpose.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>