drm: silence pointless vblank warning.
drm: silence pointless vblank warning.

Some applications/hardware combinations are triggering the message "failed to
acquire vblank counter" to be issued up to 20 times a second, which makes it
both useless and dangerous, as this may hide other important messages.
This changes makes it only appear when people are debugging.

Signed-off-by: Paul Rolland <96e3f164788cb3c54bbf71647b7f54457ec3c3fb@as2917.net>
Reviewed-by: Jesse Barnes <bc7add126c2dbb8382bf1c28ac262b9363a32706@virtuousgeek.org>
Lost-twice-by: Dave Airlie <f2295d84e358395675bc8031be58672073ae065e@redhat.com>
Signed-off-by: Dave Airlie <f2295d84e358395675bc8031be58672073ae065e@redhat.com>

KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas