nfsd to unlock kernel before exiting

The nfsd holds the big kernel lock upon exit, when it really shouldn't. Not to mention that this breaks Ingo's RT patch. This is a trivial fix to release the lock.

Ingo, this patch also works with your kernel, and stops the problem with nfsd.

Note, there's a "goto out;" where "out:" is right above svc_exit_thread. The point of the goto also holds the kernel_lock, so I don't see any problem here in releasing it.

-- Steve

@@ -287,6 +287,7 @@ out:
 	svc_exit_thread(rqstp);
 
 	/* Release module */
+	unlock_kernel();
 	module_put_and_exit(0);
 }