mii-tool.c: increase buf size in show_basic_mii()

buf concatenates what's returned from media_list()
plus couple of other strings which seems to easily
overrun the 100 byte fixed-size, therefore double it.

mii-tool.c

@@ -230,7 +230,7 @@ static const char *media_list(unsigned mask, unsigned mask2, int best)
 
 int show_basic_mii(int sock, int phy_id)
 {
-    char buf[100];
+    char buf[200];
     int i, mii_val[32];
     unsigned bmcr, bmsr, advert, lkpar, bmcr2, lpa2;