avfilter/asrc_flite: Remove double ';'

(Inside a function a stray ';' is an empty statement; outside of
a function it is actually invalid, but compilers happen to accept
it without complaint (unless e.g. using -pedantic).)

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavfilter/asrc_flite.c

@@ -71,7 +71,7 @@ static int flite_inited = 0;
 /* declare functions for all the supported voices */
 #define DECLARE_REGISTER_VOICE_FN(name) \
     cst_voice *register_cmu_us_## name(const char *); \
-    void     unregister_cmu_us_## name(cst_voice *);
+    void     unregister_cmu_us_## name(cst_voice *)
 DECLARE_REGISTER_VOICE_FN(awb);
 DECLARE_REGISTER_VOICE_FN(kal);
 DECLARE_REGISTER_VOICE_FN(kal16);