ip link gre: print only relevant info in external mode

Display only attributes that are relevant when a GRE interface is in
'external' mode instead of the default values (which are ignored by the
kernel even if passed back).

Fixes: 926b39e1 ("gre: add support for collect metadata flag")
Signed-off-by: Jiri Benc <jbenc@redhat.com>

ip/link_gre.c

@@ -339,7 +339,7 @@ get_failed:
 	return 0;
 }
 
-static void gre_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
+static void gre_print_direct_opt(FILE *f, struct rtattr *tb[])
 {
 	char s2[64];
 	const char *local = "any";
@@ -347,9 +347,6 @@ static void gre_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 	unsigned int iflags = 0;
 	unsigned int oflags = 0;
 
-	if (!tb)
-		return;
-
 	if (tb[IFLA_GRE_REMOTE]) {
 		unsigned int addr = rta_getattr_u32(tb[IFLA_GRE_REMOTE]);
 
@@ -421,8 +418,16 @@ static void gre_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 		fputs("icsum ", f);
 	if (oflags & GRE_CSUM)
 		fputs("ocsum ", f);
+}
 
-	if (tb[IFLA_GRE_COLLECT_METADATA])
+static void gre_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
+{
+	if (!tb)
+		return;
+
+	if (!tb[IFLA_GRE_COLLECT_METADATA])
+		gre_print_direct_opt(f, tb);
+	else
 		fputs("external ", f);
 
 	if (tb[IFLA_GRE_ENCAP_TYPE] &&