fix oops with -D and a single file

Reference: /n/atom/patch/applied/findoops
Date: Sat Feb 22 16:29:00 CET 2014
Signed-off-by: quanstro@quanstro.net

--- /sys/src/cmd/find.c	Sat Feb 22 16:28:55 2014
+++ /sys/src/cmd/find.c	Sat Feb 22 16:28:56 2014
@@ -105,7 +105,7 @@
 void
 find(char *name)
 {
-	int fd, n;
+	int fd, n, t;
 	Dir *buf, *p, *e;
 	char file[256];
 
@@ -115,8 +115,10 @@
 	}
 	if(!flag['D'])
 		Bprint(&out, fmt, name);
+	t = 0;
 	for(; (n = dirread(fd, &buf)) > 0; free(buf))
 		for(p = buf, e = p+n; p < e; p++){
+			t = 1;
 			snprint(file, sizeof file, "%s/%s", name, p->name);
 			if((p->qid.type&QTDIR) == 0 || !dskip(p)){
 				if(!flag['d'])
@@ -124,6 +126,8 @@
 			}else if(!skip(p))
 				find(file);
 		}
+	if(flag['D'] && !t)
+		Bprint(&out, fmt, name);
 	close(fd);
 }