Get refcounting and testing thereoff correct in std.fileread()

bin/varnishtest/tests/m00004.vtc

@@ -76,10 +76,7 @@ varnish v1 -cli "vcl.list"
 varnish v1 -cli "vcl.discard vcl1"
 
 varnish v1 -vcl+backend { }
-
-varnish v1 -cli "vcl.list"
-varnish v1 -cli "vcl.discard vcl2"
-
+varnish v1 -cli "vcl.use vcl3"
 
 client c1 {
 	txreq -url "/one"
@@ -91,3 +88,8 @@ client c1 {
 } -run
 
 varnish v1 -cli "vcl.list"
+varnish v1 -cli "vcl.discard vcl2"
+
+client c1 -run
+
+varnish v1 -cli "vcl.list"

lib/libvmod_std/vmod_std_fileread.c

@@ -37,12 +37,7 @@
  * XXX: underlying file has been updated.
  */
 
-#include <fcntl.h>
-#include <pthread.h>
 #include <stdlib.h>
-#include <unistd.h>
-#include <sys/stat.h>
-#include <sys/types.h>
 #include "vrt.h"
 #include "../../bin/varnishd/cache.h"
 
@@ -101,8 +96,11 @@ vmod_fileread(struct sess *sp, struct vmod_priv *priv, const char *file_name)
 		}
 	}
 	AZ(pthread_mutex_unlock(&frmtx));
-	if (frf != NULL)
+	if (frf != NULL) {
+		priv->free = free_frfile;
+		priv->priv = frf;
 		return (frf->contents);
+	}
 
 	s = vreadfile(NULL, file_name, NULL);
 	if (s != NULL) {