Remove one compiler warning found with -Wstrict-prototypes.
diff --git a/Modules/audioop.c b/Modules/audioop.c
index 49cd8c9..8c91617 100644
--- a/Modules/audioop.c
+++ b/Modules/audioop.c
@@ -40,7 +40,7 @@
                         else if ( x > MAXLIN ) x = MAXLIN; \
                       } while ( 0 )
 
-static unsigned char st_linear_to_ulaw( /* int sample */ );
+static unsigned char st_linear_to_ulaw(int sample);
 
 /*
 ** This macro converts from ulaw to 16 bit linear, faster.