added <errno.h> dependency

programs/dibio.c

@@ -30,6 +30,7 @@
 #include <string.h>         /* memset */
 #include <stdio.h>          /* fprintf, fopen, ftello64 */
 #include <time.h>           /* clock_t, clock, CLOCKS_PER_SEC */
+#include <errno.h>          /* errno */
 
 #include "mem.h"            /* read */
 #include "error_private.h"