TBR: global: eliminate "tam"

I missed one spot with my previous CL.
("tam" stood for TaggedACLMap. TaggedACLMap was renamed
Permissions.)

Change-Id: I7a44ad096c73865309d7039b1438b97f64578e32
diff --git a/lib/security/securityflag/flag.go b/lib/security/securityflag/flag.go
index 0c7b3fc..dea39a0 100644
--- a/lib/security/securityflag/flag.go
+++ b/lib/security/securityflag/flag.go
@@ -45,9 +45,9 @@
 	if literal == "" {
 		a, err = access.PermissionsAuthorizerFromFile(fname, access.TypicalTagType())
 	} else {
-		var tam access.Permissions
-		if tam, err = access.ReadPermissions(bytes.NewBufferString(literal)); err == nil {
-			a, err = access.PermissionsAuthorizer(tam, access.TypicalTagType())
+		var perms access.Permissions
+		if perms, err = access.ReadPermissions(bytes.NewBufferString(literal)); err == nil {
+			a, err = access.PermissionsAuthorizer(perms, access.TypicalTagType())
 		}
 	}
 	if err != nil {