drm/arm: make hdlcd_debugfs_init() return 0

drm/arm: make hdlcd_debugfs_init() return 0

Since commit 987d65d01356 (drm: debugfs: make
drm_debugfs_create_files() never fail), drm_debugfs_create_files() never
fails and should return void. Therefore, remove its use as the
return value of hdlcd_debugfs_init() and have the latter function return
0 directly.

v2: make hdlcd_debugfs_init() return 0 instead of void to ensure that
each patch compiles individually.

References: https://lists.freedesktop.org/archives/dri-devel/2020-February/257183.html
Signed-off-by: Wambui Karuga <wambui.karugax@gmail.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200310133121.27913-7-wambui.karugax@gmail.com