Include stdio.h in torerr.c.

src/lib/err/torerr.c

@@ -15,6 +15,7 @@
 #include <stdarg.h>
 #include <stdlib.h>
 #include <string.h>
+#include <stdio.h>
 #ifdef HAVE_SYS_TIME_H
 #include <sys/time.h>
 #endif