Allow bigger filenames

Not that I know why. 80-character filename limits are kind of cute.

Joerg suggested _POSIX_PATH_MAX, which is almost certainly the right
value.  But that's bigger than HUGE:

   #define HUGE    1000           /* Huge number                  */

which obviously means we shouldn't go quite *that* extreme.

Remember, we come from the days when it was hard to do allocations
larger than 64kB.   We have limits, dammit.

"256 bytes is enough for anybody"

Reported-by: Joerg Scheurich <mufti11@web.de>
Signed-off-by: Linus Torvalds <torvalds@linux-coundation.org>
diff --git a/estruct.h b/estruct.h
index 8240f78..bcef6d8 100644
--- a/estruct.h
+++ b/estruct.h
@@ -226,7 +226,7 @@
 /* Internal constants. */
 
 #define	NBINDS	256		/* max # of bound keys          */
-#define NFILEN  80		/* # of bytes, file name        */
+#define NFILEN  256		/* # of bytes, file name        */
 #define NBUFN   16		/* # of bytes, buffer name      */
 #define NLINE   256		/* # of bytes, input line       */
 #define	NSTRING	128		/* # of bytes, string buffers   */