Fix buffer overflow in get_module()

get_module() includes this scanf call:

  if (sscanf(buf, "%*d\t%*s\t%100s\t%*d\t%100s\n", driver, dev) > 0) {

i.e. "%100s" for each of driver and dev.  i.e. a maximum field width of
100 for each.

However, this field width does not include the NUL terminator.

Increase the size of driver and dev from 100 to 101 to allow for the NUL byte.

This appears to have been present in the initial commit of the code
(8d6ad99)

Found by Braňo Náter using the "cppcheck" static analyzer.

Author: davidmalcolm

python-ethtool/ethtool.c

@@ -500,7 +500,7 @@ static PyObject *get_module(PyObject *self __unused, PyObject *args)
 		int eno = errno;
 		FILE *file;
 		int found = 0;
-		char driver[100], dev[100];
+		char driver[101], dev[101];
 		close(fd);
 
 		/* Before bailing, maybe it is a PCMCIA/PC Card? */