Delete redundant enum values for lock types.
For lock type, we only need one internal value to specify cases when currently there is no passive lock issued from origin side or there is no passive lock imposed on target side. If there are passive locks, we directly use MPI_LOCK_SHARED and MPI_LOCK_EXCLUSIVE to indicate the lock type. This patch deletes redundant enum for lock types and just defines MPID_LOCK_NONE. Signed-off-by: Rob Latham <firstname.lastname@example.org>