Long line bug in lex

[Joe Kelsey]

Index:	usr.bin/lex/header.c 4.2BSD

Description:
	Lines longer than 200 characters overflow lex line buffers,
	wreaking havoc in other data structures.
Repeat-By:
	Take the pathalias software as distributed and try out the
	new uucp maps.  Notice how things fall apart very quickly.
Fix:
	Replace the #define YYLMAX 200 in function chd1 in header.c
	with #define YYLMAX BUFSIZ.  This will allow a more reasonable
	line limit and try to prevent overflowing buffers.  Grumble about
	sloppy programmers who can't use big buffers or dynamically 
	allow for larger limits.