Any developer that adds a new user without setting rq_task will get a
crash the first time they test it. I also don't think there are
normally any important locks held here, and I can't see any other reason
why killing a server thread would bring the whole box down.
So the effort to fail gracefully here looks like overkill.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Fixes: 983c684466e0 "SUNRPC: get rid of the request wait queue" Signed-off-by: J. Bruce Fields <bfields@redhat.com>