Have a different approach on how to check if the modules file has changed.

Because the $FreeBSD$ keyword isn't expanded in the new version, we can't
just do a diff, check the return value and ignore the output.

Every new modules file, changed or not with regarding to the contents,
has at least four lines in the diff output (line number, old line,
seperator, new line). Only commit it if there are more than four
lines difference between it.

Tools/scripts/modules/update.sh

@@ -1,22 +1,20 @@
 #!/bin/sh
 
-# $FreeBSD$
-
 cd /g/hubgnats/gnats-aa/modules
 
 make clean
 make
 
-pl=`wc -l modules-ports | awk '{ print $1 }'`
-ml=`wc -l modules | awk '{ print $1 }'`
-diff=`expr $pl - $ml`
-if [ $diff -lt 0 ]; then
-	diff=`expr 0 - $diff`
-fi
+diff=`diff modules-ports modules | wc | awk '{ print $1 }'`
+
 echo Difference is $diff lines.
+
 if [ $diff -gt 50 ]; then
 	date | mail -s "DIFF > $diff" edwin@FreeBSD.org
 	exit
 fi
 
-make commit
+# Don't commit anything if only the $FreeBSD$ tag has changed
+if [ $diff -ne 4 ]; then
+	make commit
+fi