Fixed some compile-breaking mistakes.

src/include/86box/hdc.h

@@ -28,6 +28,9 @@
                       * least 7 devices, with each device being  \
                       * able to support 8 units, but hey... */
 
+#define HDC_NONE     0
+#define HDC_INTERNAL 1
+
 extern int hdc_current;
 
 extern const device_t st506_xt_xebec_device;         /* st506_xt_xebec */

src/machine/m_xt_olivetti.c

@@ -1189,7 +1189,7 @@ machine_xt_m240_init(const machine_t *model)
 
     mm58274_init(nvr, model->nvrmask + 1);
 
-    if (hdc_type == HDC_INTERNAL)
+    if (hdc_current == HDC_INTERNAL)
         device_add(&st506_xt_wd1002a_wx1_nobios_device);
 
     return ret;