afs: Make record checking use TASK_UNINTERRUPTIBLE when appropriate

commit c4bfda16 upstream.

When an operation is meant to be done uninterruptibly (such as
FS.StoreData), we should not be allowing volume and server record checking
to be interrupted.

Fixes: d2ddc776 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>