drm/tilcdc: remove check for return value of debugfs functions.

Since 987d65d013 (drm: debugfs: make
drm_debugfs_create_files() never fail), drm_debugfs_create_files() never
fails. Therefore, remove the check and error handling of the return
value of drm_debugfs_create_files() as it is not needed in
tilcdc_debugfs_init().

Also remove local variables that are not used after the changes.

v2: remove conversion of tilcdc_debugfs_init() to void to avoid build
breakage and enable individual compilation.

References: https://lists.freedesktop.org/archives/dri-devel/2020-February/257183.html
Signed-off-by: Wambui Karuga <wambui.karugax@gmail.com>
Acked-by: Jyri Sarha <jsarha@ti.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/20200310133121.27913-3-wambui.karugax@gmail.com

drivers/gpu/drm/tilcdc/tilcdc_drv.c

@@ -480,11 +480,9 @@ static struct drm_info_list tilcdc_debugfs_list[] = {
 
 static int tilcdc_debugfs_init(struct drm_minor *minor)
 {
-	struct drm_device *dev = minor->dev;
 	struct tilcdc_module *mod;
-	int ret;
 
-	ret = drm_debugfs_create_files(tilcdc_debugfs_list,
+	drm_debugfs_create_files(tilcdc_debugfs_list,
 				 ARRAY_SIZE(tilcdc_debugfs_list),
 				 minor->debugfs_root, minor);
 
@@ -492,12 +490,7 @@ static int tilcdc_debugfs_init(struct drm_minor *minor)
 		if (mod->funcs->debugfs_init)
 			mod->funcs->debugfs_init(mod, minor);
 
-	if (ret) {
-		dev_err(dev->dev, "could not install tilcdc_debugfs_list\n");
-		return ret;
-	}
-
-	return ret;
+	return 0;
 }
 #endif