fix botch in nupas conversion.  need to set the file name after
finding the match.

Reference: /n/atom/patch/applied/filterfix
Date: Sat Mar  1 23:24:44 CET 2014
Signed-off-by: quanstro@quanstro.net

--- /sys/src/cmd/upas/send/filter.c	Sat Mar  1 23:24:20 2014
+++ /sys/src/cmd/upas/send/filter.c	Sat Mar  1 23:24:21 2014
@@ -34,7 +34,7 @@
 void
 usage(void)
 {
-	fprint(2, "usage: upas/filter [-bh] rcvr mailbox [regexp file] ...\n");
+	fprint(2, "usage: upas/filter [-nbh] rcvr mailbox [regexp file] ...\n");
 	exits("usage");
 }
 
@@ -50,6 +50,9 @@
 
 	header = body = 0;
 	ARGBEGIN {
+	case 'n':
+		flagn = 1;
+		break;
 	case 'h':
 		header = 1;
 		break;
@@ -73,9 +76,6 @@
 		mp->sender = s_copy(cp);
 	}
 
-	dp = d_new(s_copy(argv[0]));
-	dp->repl1 = s_copy(argv[1]);
-
 	strecpy(file, file+sizeof file, argv[1]);
 	cp = findbody(s_to_c(mp->body));
 	for(i = 2; i < argc; i += 2){
@@ -95,6 +95,8 @@
 			break;
 		}
 	}
+	dp = d_new(s_copy(argv[0]));
+	dp->repl1 = s_copy(file);
 	if(cat_mail(dp, mp) != 0)
 		exits("fail");
 	exits("");