staging/lustre/llite: fix open lock matching in ll_md_blocking_ast()
In ll_md_blocking_ast() match open locks before all others, ensuring
that MDS_INODELOCK_OPEN is not cleared from bits by another open lock
with a different mode. Change the int flags parameter of
ll_md_real_close() to fmode_t fmode. Clean up verious style issues in
both functions.