drm: print the current->comm alongside the pid

The question of "what process is this pid" keeps on popping up, so lets
print the process name alongside the pid.

Cc: Mauro Rossi <issor.oruam@gmail.com>
Cc: Bob Beckett <bob.beckett@collabora.com>
Cc: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200518083315.129948-1-emil.l.velikov@gmail.com