afs: Remove whitespace before most ')' from the trace header

checkpatch objects to whitespace before ')', so remove most of it from the
afs trace header.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-afs@lists.infradead.org
cc: linux-fsdevel@vger.kernel.org