mklatinkbd: fix buffer overflow

Fixes #71.

R=rsc
CC=codebot
http://codereview.appspot.com/4327057

src/cmd/devdraw/mklatinkbd.c

@@ -31,7 +31,7 @@ char *head = ""
 typedef struct Trie	Trie;
 struct Trie {
 	int n; /* of characters r */
-	char seq[MAXLD+1];
+	char seq[MAXLD+1+1];
 	Rune r[256];
 	Trie *link[256];
 };