maintainers: general@lists.openfabrics.org is moderated

I got the "list is moderated message," so add it here.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>