drm/virtio: Add blank line after variable declarations

This patch fixes the checkpatch.pl warnings:

virtgpu_drv.c:57: WARNING: Missing a blank line after declarations
virtgpu_display.c:99: WARNING: Missing a blank line after declarations
...

Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/41767852ff9dc584c825e32db6222b9a311603b9.1519343668.git.rodrigosiqueiramelo@gmail.com


Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>