dlm: proper types for asts and basts

Use proper types for ast and bast functions, and use
consistent type for ast param.

Signed-off-by: David Teigland <teigland@redhat.com>

diff --cc fs/dlm/ast.c
Simple merge

diff --cc fs/dlm/dlm_internal.h
Simple merge

diff --cc fs/dlm/lock.c
Simple merge

diff --cc fs/dlm/rcom.c
Simple merge