drm/print: Unconfuse kerneldoc

drm/print: Unconfuse kerneldoc

It thinks we want to document the __printf(2,0) annotion. Not sure we
want to teach it about all possible gcc-only flags, hence why I opted
for the cheap trick of just moving it ahead of the kerneldoc.

This is only a problem for static inline functions, since for
non-inline function the kerneldoc is in the .c file, but the special
annotations are all in the header.

Cc'ing kernel-doc maintainers as fyi.

Cc: linux-doc@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171214203054.20141-3-daniel.vetter@ffwll.ch