Fix compilation errors.

src/Makefile.am

@@ -45,7 +45,8 @@ nodist_EXTRA_libmediastreamer_base_la_SOURCES = dummy.cxx
 
 if ORTP_ENABLED
 BUILT_SOURCES+=voipdescs.h
-libmediastreamer_voip_la_SOURCES+=	msvoip.c \
+libmediastreamer_voip_la_SOURCES+=	private.h \
+					msvoip.c \
 					mediastream.c \
 					audiostream.c \
 					ringstream.c \

src/mediastream.c

@@ -146,7 +146,7 @@ void start_ticker(MediaStream *stream) {
 	stream->ticker = ms_ticker_new_with_params(&params);
 }
 
-const char * const media_stream_type_str(MediaStream *stream) {
+const char * media_stream_type_str(MediaStream *stream) {
 	switch (stream->type) {
 		default:
 		case AudioStreamType:

src/private.h

@@ -35,7 +35,7 @@ void start_ticker(MediaStream *stream);
 
 void payload_type_changed(RtpSession *session, unsigned long data);
 
-const char * const media_stream_type_str(MediaStream *stream);
+const char * media_stream_type_str(MediaStream *stream);
 
 void media_stream_free(MediaStream *stream);