drm: remove unused dev variables

drm: remove unused dev variables

After drm_gem_object_lookup() was changed along with all its callers,
we have several drivers that have unused variables:

drm/armada/armada_crtc.c: In function 'armada_drm_crtc_cursor_set':
drm/armada/armada_crtc.c:900:21: error: unused variable 'dev' [-Werror=unused-variable]
drm/nouveau/nouveau_gem.c: In function 'validate_init':
drm/nouveau/nouveau_gem.c:371:21: error: unused variable 'dev' [-Werror=unused-variable]
drm/nouveau/nv50_display.c: In function 'nv50_crtc_cursor_set':
drm/nouveau/nv50_display.c:1308:21: error: unused variable 'dev' [-Werror=unused-variable]
drm/radeon/radeon_cs.c: In function 'radeon_cs_parser_relocs':
drm/radeon/radeon_cs.c:77:21: error: unused variable 'ddev' [-Werror=unused-variable]

This fixes all the instances I found with ARM randconfig builds so far.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: a8ad0bd84f98 ("drm: Remove unused drm_device from drm_gem_object_lookup()")
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1463587653-3035181-6-git-send-email-arnd@arndb.de