Corrected grammar.

bacnet-stack/demo/mstpcap/main.c

@@ -459,7 +459,7 @@ int main(
 
     /* initialize our interface */
     if ((argc > 1) && (strcmp(argv[1], "--help") == 0)) {
-        printf("mstpcap [inteface] [baud]\r\n"
+        printf("mstpcap [interface] [baud]\r\n"
             "Captures MS/TP packets from a serial interface\r\n"
             "and save them to a file. Saves packets in a\r\n"
             "filename mstp_20090123091200.cap that has data and time.\r\n"

bacnet-stack/ports/linux/mstpsnap.c

@@ -271,7 +271,7 @@ int main(
             "\r\n"
             "Command line options:\r\n"
             "[serial] - serial interface.\r\n"
-            "    defaults to COM4 on  Windows, and /dev/ttyUSB0 on linux.\r\n"
+            "    defaults to /dev/ttyUSB0.\r\n"
             "[baud] - baud rate.  9600, 19200, 38400, 57600, 115200\r\n"
             "    defaults to 38400.\r\n"
             "[network] - network interface.\r\n"