godoc documentation: fixed typo, more precise comment

R=iant
CC=golang-dev
https://golang.org/cl/2184042

src/cmd/godoc/doc.go

@@ -62,9 +62,9 @@ The flags are:
 	-sync_minutes=0
 		sync interval in minutes; sync is disabled if <= 0
 	-filter=""
-		file containing permitted permitted directory paths
+		filter file containing permitted package directory paths
 	-filter_minutes=0
-		filter update interval in minutes; update is disabled if <= 0
+		filter file update interval in minutes; update is disabled if <= 0
 
 The -path flag accepts a list of colon-separated paths; unrooted paths are relative
 to the current working directory. Each path is considered as an additional root for

src/cmd/godoc/godoc.go

@@ -53,8 +53,8 @@ var (
 	// file system roots
 	goroot      = flag.String("goroot", runtime.GOROOT(), "Go root directory")
 	path        = flag.String("path", "", "additional package directories (colon-separated)")
-	filter      = flag.String("filter", "godoc.dirlist", "file containing permitted package directory paths")
-	filterMin   = flag.Int("filter_minutes", 0, "filter update interval in minutes; disabled if <= 0")
+	filter      = flag.String("filter", "godoc.dirlist", "filter file containing permitted package directory paths")
+	filterMin   = flag.Int("filter_minutes", 0, "filter file update interval in minutes; disabled if <= 0")
 	filterDelay delayTime // actual filter update interval in minutes; usually filterDelay == filterMin, but filterDelay may back off exponentially
 
 	// layout control