The routines that implement a codec don't need to be public.

Pointers to them are passed to register_codec(), so they can be static
to l16decode.c.

Change-Id: I2303cc4374e81a2e5a77eaa275ca601d99a4f608
Reviewed-on: https://code.wireshark.org/review/26355
Reviewed-by: Guy Harris <guy@alum.mit.edu>

plugins/codecs/l16_mono/l16decode.c

@@ -16,31 +16,31 @@
 #include "codecs/codecs.h"
 #include "ws_attributes.h"
 
-void *
+static void *
 codec_l16_init(void)
 {
     return NULL;
 }
 
-void
+static void
 codec_l16_release(void *ctx _U_)
 {
 
 }
 
-unsigned
+static unsigned
 codec_l16_get_channels(void *ctx _U_)
 {
     return 1;
 }
 
-unsigned
+static unsigned
 codec_l16_get_frequency(void *ctx _U_)
 {
     return 44100;
 }
 
-size_t
+static size_t
 codec_l16_decode(void *ctx _U_, const void *input, size_t inputSizeBytes,
                  void *output, size_t *outputSizeBytes)
 {