Use const consistently for function parameters

This commit fixes several MSVC build warnings.

Change-Id: Ib75dd63e6de3cc3e370ec676c9cb9c358b41c4ae
diff --git a/av1/encoder/encoder.c b/av1/encoder/encoder.c
index 16bd6a0..989c6e1 100644
--- a/av1/encoder/encoder.c
+++ b/av1/encoder/encoder.c
@@ -3991,8 +3991,8 @@
   }
 }
 
-void av1_set_screen_content_options(const AV1_COMP *const cpi,
-                                    FeatureFlags *const features) {
+void av1_set_screen_content_options(const AV1_COMP *cpi,
+                                    FeatureFlags *features) {
   const AV1_COMMON *const cm = &cpi->common;
 
   if (cm->seq_params.force_screen_content_tools != 2) {