Correct locked flag after svc_rqst_evchan_unreg.

The routine calls SVC_RELEASE, which releases xprt->xp_lock.

Found while investigating Coverity CID 23131.

Signed-off-by: Matt Benjamin <matt@linuxbox.com>
Update ntirpc submodule.

Take fixes for Coverity defects reported against rc5.

Signed-off-by: Matt Benjamin <matt@linuxbox.com>