reverse: fix TestXattrList failure

On my Fedora I used to get this failure:

	--- FAIL: TestXattrList (0.00s)
	    xattr_test.go:52: wrong number of names, want=20 have=21
	    xattr_test.go:58: mismatch on attr "security.selinux": valA = "", valC = "xxxxxxxxyyyyyyyyyyyyyyyzzzzzzzzzzzzz"

First step is to print the actual value using xattr.LGet.
This improves the error message to this:

	--- FAIL: TestXattrList (0.00s)
	    xattr_test.go:53: wrong number of names, want=20 have=21
	    xattr_test.go:59: mismatch on attr "security.selinux": valA = "", valC = "system_u:object_r:fusefs_t:s0\x00"

2nd step is to ignore "security." attribs as we have no control
over them.

1 files changed, 7 insertions, 1 deletions

diff --git a/tests/reverse/xattr_test.go b/tests/reverse/xattr_test.go
index df7724f..406d055 100644
--- a/tests/reverse/xattr_test.go
+++ b/tests/reverse/xattr_test.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"strings"
 	"syscall"
 	"testing"
 
@@ -46,7 +47,12 @@ func TestXattrList(t *testing.T) {
 	}
 	namesC := map[string]string{}
 	for _, n := range tmp {
-		namesC[n] = string(val)
+		if strings.HasPrefix(n, "security.") {
+			t.Logf("Ignoring xattr %q", n)
+			continue
+		}
+		v, _ := xattr.LGet(fnC, n)
+		namesC[n] = string(v)
 	}
 	if len(namesA) != len(namesC) {
 		t.Errorf("wrong number of names, want=%d have=%d", len(namesA), len(namesC))