Commit c8ee0a44 introduced new events containing PRIx64 constants without
including the % prefix in the preceding string. This results in a compile
error during build if --enable-trace-backends is passed to configure.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-id: 1450566522-6003-1-git-send-email-mark.cave-ayland@ilande.co.uk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>