Mark some functions static.

These were only non-static because of oversight.

src/http.c

@@ -1527,7 +1527,7 @@ static BIO_METHOD op_bio_retry_method={
 
 /*Establish a CONNECT tunnel and pipeline the start of the TLS handshake for
    proxying https URL requests.*/
-int op_http_conn_establish_tunnel(OpusHTTPStream *_stream,
+static int op_http_conn_establish_tunnel(OpusHTTPStream *_stream,
  OpusHTTPConn *_conn,op_sock _fd,SSL *_ssl_conn,BIO *_ssl_bio){
   BIO  *retry_bio;
   char *status_code;
@@ -1796,7 +1796,7 @@ static int op_http_verify_hostname(OpusHTTPStream *_stream,SSL *_ssl_conn){
 }
 
 /*Perform the TLS handshake on a new connection.*/
-int op_http_conn_start_tls(OpusHTTPStream *_stream,OpusHTTPConn *_conn,
+static int op_http_conn_start_tls(OpusHTTPStream *_stream,OpusHTTPConn *_conn,
  op_sock _fd,SSL *_ssl_conn){
   SSL_SESSION *ssl_session;
   BIO         *ssl_bio;

src/info.c

@@ -101,7 +101,7 @@ void opus_tags_clear(OpusTags *_tags){
   Unlike the public API, this function requires _tags to already be
    initialized, modifies its contents before success is guaranteed, and assumes
    the caller will clear it on error.*/
-int opus_tags_parse_impl(OpusTags *_tags,
+static int opus_tags_parse_impl(OpusTags *_tags,
  const unsigned char *_data,size_t _len){
   opus_uint32 count;
   size_t      size;

src/opusfile.c

@@ -1003,7 +1003,7 @@ static int op_find_final_pcm_offset(OggOpusFile *_of,
 
 /*Rescale the number _x from the range [0,_from] to [0,_to].
   _from and _to must be positive.*/
-opus_int64 op_rescale64(opus_int64 _x,opus_int64 _from,opus_int64 _to){
+static opus_int64 op_rescale64(opus_int64 _x,opus_int64 _from,opus_int64 _to){
   opus_int64 frac;
   opus_int64 ret;
   int        i;