avconv/avprobe: Add missing 'void' to exit_program() definition

avconv.c

@@ -143,7 +143,7 @@ static int decode_interrupt_cb(void *ctx)
 
 const AVIOInterruptCB int_cb = { decode_interrupt_cb, NULL };
 
-static void exit_program()
+static void exit_program(void)
 {
     int i, j;
 

avprobe.c

@@ -59,7 +59,7 @@ static const char unit_hertz_str[]          = "Hz"   ;
 static const char unit_byte_str[]           = "byte" ;
 static const char unit_bit_per_second_str[] = "bit/s";
 
-static void exit_program()
+static void exit_program(void)
 {
     av_dict_free(&fmt_entries_to_show);
 }