fix: added missing file pointer to fputc() call

src/common/header.c

@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: header.c,v 2.39 2020/07/24 16:58:16 greg Exp $";
+static const char	RCSid[] = "$Id: header.c,v 2.40 2020/07/25 01:10:38 greg Exp $";
 #endif
 /*
  *  header.c - routines for reading and writing information headers.
@@ -171,9 +171,9 @@ printargs(		/* print arguments to a file */
 	extern char	*fixargv0(char *arg0);
 	char		myav0[128];
 				/* clean up Windows executable path */
-	if (ac <= 0) return;
+	if (ac-- <= 0) return;
 	fputs(fixargv0(strcpy(myav0, *av++)), fp);
-	fputc(--ac ? ' ' : '\n');
+	fputc(ac ? ' ' : '\n', fp);
 #endif
 	while (ac-- > 0) {
 		fputword(*av++, fp);