vp10/encoder/bitstream.[hc]: correct a prototype

quiets a -Wmissing-prototypes warning

BUG=b/29584271

Change-Id: I91aba2a75dccd6752bdf91837564c2aa45817c09

vp10/encoder/bitstream.c

diff --git a/vp10/encoder/bitstream.c b/vp10/encoder/bitstream.c
index 389e40b..3999c94 100644
--- a/vp10/encoder/bitstream.c
+++ b/vp10/encoder/bitstream.c
@@ -121,7 +121,7 @@
 static struct vp10_token motvar_encodings[MOTION_VARIATIONS];
 #endif  // CONFIG_OBMC || CONFIG_WARPED_MOTION
 
-void vp10_encode_token_init() {
+void vp10_encode_token_init(void) {
 #if CONFIG_EXT_TX
   int s;
   for (s = 1; s < EXT_TX_SETS_INTER; ++s) {

vp10/encoder/bitstream.h

diff --git a/vp10/encoder/bitstream.h b/vp10/encoder/bitstream.h
index 0284920..cacdb43 100644
--- a/vp10/encoder/bitstream.h
+++ b/vp10/encoder/bitstream.h
@@ -20,7 +20,7 @@
 
 void vp10_pack_bitstream(VP10_COMP *const cpi, uint8_t *dest, size_t *size);
 
-void vp10_encode_token_init();
+void vp10_encode_token_init(void);
 
 static INLINE int vp10_preserve_existing_gf(VP10_COMP *cpi) {
   return !cpi->multi_arf_allowed && cpi->refresh_golden_frame &&