fix cflags

src/cmd/postscript/download/mkfile

diff --git a/src/cmd/postscript/download/mkfile b/src/cmd/postscript/download/mkfile
index d448b4f..f3b8b73 100644
--- a/src/cmd/postscript/download/mkfile
+++ b/src/cmd/postscript/download/mkfile
@@ -17,7 +17,7 @@
 BIN=$POSTBIN
 
 <$PLAN9/src/mkone
-CFLAGS=-c -D$SYSTEM -D_POSIX_SOURCE -I$COMMONDIR
+CFLAGS=-Dplan9 -I$COMMONDIR
 
 $LIB:
 	cd $COMMONDIR