clean up when finished.
don't set PLAN9
diff --git a/src/cmd/dict/mkfile b/src/cmd/dict/mkfile
index 603ba60..8292a1f 100644
--- a/src/cmd/dict/mkfile
+++ b/src/cmd/dict/mkfile
@@ -1,4 +1,3 @@
-PLAN9=../../..
 <$PLAN9/src/mkhdr
 
 TARG=dict
diff --git a/src/cmd/diff/mkfile b/src/cmd/diff/mkfile
index 6445f9d..feb3a04 100644
--- a/src/cmd/diff/mkfile
+++ b/src/cmd/diff/mkfile
@@ -1,4 +1,3 @@
-PLAN9=../../..
 <$PLAN9/src/mkhdr
 
 TARG=diff