drivers: video: fbcmap: remove the redundency and incorrect checkings

fb_set_cmap() already checks the parameters, so need remove the
redundancy checking.

This redundancy checking is also incorrect, the related warning:

  drivers/video/fbcmap.c:288:2: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/fbcmap.c

@@ -285,13 +285,8 @@ int fb_set_user_cmap(struct fb_cmap_user *cmap, struct fb_info *info)
 		rc = -ENODEV;
 		goto out;
 	}
-	if (cmap->start < 0 || (!info->fbops->fb_setcolreg &&
-				!info->fbops->fb_setcmap)) {
-		rc = -EINVAL;
-		goto out1;
-	}
+
 	rc = fb_set_cmap(&umap, info);
-out1:
 	unlock_fb_info(info);
 out:
 	fb_dealloc_cmap(&umap);