Fix implicit gnu89 inline semantics causing issues with clang:
* main.o:main.c:function main: error: undefined reference to 'AuChannelOpen'
* https://bugs.gentoo.org/show_bug.cgi?id=458932

--- libaacplus-2.0.2/frontend/au_channel.h
+++ libaacplus-2.0.2/frontend/au_channel.h
@@ -12,7 +12,7 @@
 	int	aFmt;
 } WavInfo;
 
-inline FILE* AuChannelOpen (const char* filename, WavInfo* info)
+static inline FILE* AuChannelOpen (const char* filename, WavInfo* info)
 {
 	unsigned char header[12];
 	unsigned char data[WAV_HEADER_SIZE];
@@ -48,18 +48,18 @@
 	return handle;
 }
 
-inline void AuChannelClose (FILE *audioChannel)
+static inline void AuChannelClose (FILE *audioChannel)
 {
 	fclose(audioChannel);
 }
 
-inline size_t AuChannelReadShort(FILE *audioChannel, short *samples, int nSamples, int *readed)
+static inline size_t AuChannelReadShort(FILE *audioChannel, short *samples, int nSamples, int *readed)
 {
 	*readed = fread(samples, 2, nSamples, audioChannel);
 	return *readed <= 0;
 }
 
-inline size_t AuChannelReadFloat(FILE *audioChannel, float *samples, int nSamples, int *readed)
+static inline size_t AuChannelReadFloat(FILE *audioChannel, float *samples, int nSamples, int *readed)
 {
 	*readed = fread(samples, 4, nSamples, audioChannel);
 	return *readed <= 0;