Fixed spelling errors detected by code-spell utility. (#895)

* Fixed spelling errors detected by code-spell utility.

* Fixed cppcheck preprocessorErrorDirective. Suppressed new cppcheck warnings until fixed.

src/bacnet/datalink/bsc/bsc-node.c

@@ -6,6 +6,7 @@
  * @copyright SPDX-License-Identifier: MIT
  */
 #include "bacnet/basic/sys/debug.h"
+#include "bacnet/datalink/bsc/bsc-conf.h"
 #include "bacnet/datalink/bsc/bsc-node.h"
 #include "bacnet/datalink/bsc/bsc-event.h"
 #include "bacnet/datalink/bsc/bsc-util.h"
@@ -48,7 +49,7 @@ struct BSC_Node {
     BACNET_SC_HUB_FUNCTION_CONNECTION_STATUS *hub_status;
 };
 
-#if BSC_CONF_NODES_NUM < 1
+#if defined(BSC_CONF_NODES_NUM) && (BSC_CONF_NODES_NUM < 1)
 #error "BSC_CONF_NODES_NUM must be >= 1"
 #endif