Missing void declarations in various function parameter added.

tools/check.c

@@ -26,7 +26,7 @@
 
 #include "ebus-decode.h"
 
-int main() {
+int main(void) {
 
 	int i, j, end, ret;
 

tools/csv.c

@@ -42,7 +42,7 @@ static char loglevel[] = {"ALL"};
 
 
 void
-usage()
+usage(void)
 {
 	fprintf(stdout, "\nUsage: %s [OPTION] cfgdir\n\n"
 	"  -a --all      print ALL\n"

tools/ebus_send.c

@@ -55,7 +55,7 @@ print_msg(const char *pre, const unsigned char *buf, int buflen,
 }
 
 void
-usage()
+usage(void)
 {
 	fprintf(stdout, "\nUsage: %s [OPTION] <ZZ PB SB NN DBx>\n\n"
 	"  <ZZ PB SB NN DBx>  spaces within message be removed.\n\n"