Update trimlast2 to expect fixed behaviour

Author: twaugh

tests/trimlast2/run-test

@@ -35,8 +35,8 @@ ${COMBINEDIFF} patch1 patch2 > patch12 2>errors || exit 1
 [ -s errors ] && exit 1
 
 cat << EOF | cmp - patch12 || exit 1
-diff -u file file
---- file
+diff -u file.orig file
+--- file.orig
 +++ file
 @@ -1,4 +1,4 @@
 -0