svc examples: resolve missing declarations

BUG=webm:1584

Change-Id: Icb7ba5bb5a6d460c4d0419b76ee54af461ca4a52

examples/svc_encodeframe.c

@@ -280,8 +280,8 @@ vpx_codec_err_t vpx_svc_set_options(SvcContext *svc_ctx, const char *options) {
   return VPX_CODEC_OK;
 }
 
-vpx_codec_err_t assign_layer_bitrates(const SvcContext *svc_ctx,
-                                      vpx_codec_enc_cfg_t *const enc_cfg) {
+static vpx_codec_err_t assign_layer_bitrates(
+    const SvcContext *svc_ctx, vpx_codec_enc_cfg_t *const enc_cfg) {
   int i;
   const SvcInternal_t *const si = get_const_svc_internal(svc_ctx);
   int sl, tl, spatial_layer_target;

examples/vp9_spatial_svc_encoder.c

@@ -539,8 +539,9 @@ static void printout_rate_control_summary(struct RateControlStats *rc,
          tot_num_frames);
 }
 
-vpx_codec_err_t parse_superframe_index(const uint8_t *data, size_t data_sz,
-                                       uint64_t sizes[8], int *count) {
+static vpx_codec_err_t parse_superframe_index(const uint8_t *data,
+                                              size_t data_sz, uint64_t sizes[8],
+                                              int *count) {
   // A chunk ending with a byte matching 0xc0 is an invalid chunk unless
   // it is a super frame index. If the last byte of real video compression
   // data is 0xc0 the encoder must add a 0 byte. If we have the marker but