tests: in46a_test: Make coverity happy when calling in46a_from_eua

Coverity warns around that test code:
"Overrunning struct type in46_addr of 20 bytes by passing it to a
function which accesses it at byte offset 39."

That's basically because in64a_from_eua expects to be passed a 2 element
array to be filled. The second element, though, is only accessed in the
case where an IPv4v6 EUA is passed, so in the cases where the test
explicitly passes an IPv4 or IPv6 EUA it's not really an issue, hence
coverity throwing a false positive here.
Let's anyway rewrite the code to pass a 2 element array for completeness,
since it doesn't hurt and makes coverity happy.

Related: Coverity CID#249006
Change-Id: Idfc9104f48eeee6e7f11ebc5c17d4b0e4b2fe9e2

tests/lib/in46a_test.c

@@ -146,7 +146,7 @@ static void test_in46a_to_eua(void)
 
 static void test_in46a_from_eua(void)
 {
-	struct in46_addr ia;
+	struct in46_addr ia[2];
 	struct ul66_t eua;
 	const uint8_t v4_unspec[] = { PDP_EUA_ORG_IETF, PDP_EUA_TYPE_v4 };
 	const uint8_t v4_spec[] = { PDP_EUA_ORG_IETF, PDP_EUA_TYPE_v4, 1,2,3,4 };
@@ -155,35 +155,35 @@ static void test_in46a_from_eua(void)
 	printf("Testing in46a_from_eua() with IPv4 addresses\n");
 
 	/* default: v4 unspec */
-	OSMO_ASSERT(in46a_from_eua(&eua, &ia) == 1);
-	OSMO_ASSERT(ia.len == 4);
-	OSMO_ASSERT(ia.v4.s_addr == 0);
+	OSMO_ASSERT(in46a_from_eua(&eua, ia) == 1);
+	OSMO_ASSERT(ia[0].len == 4);
+	OSMO_ASSERT(ia[0].v4.s_addr == 0);
 
 	/* invalid */
 	eua.v[0] = 0x23;
 	eua.v[1] = PDP_EUA_TYPE_v4;
 	eua.l = 6;
-	OSMO_ASSERT(in46a_from_eua(&eua, &ia) < 0);
+	OSMO_ASSERT(in46a_from_eua(&eua, ia) < 0);
 
 	/* invalid */
 	eua.v[0] = PDP_EUA_ORG_IETF;
 	eua.v[1] = 0x23;
 	eua.l = 6;
-	OSMO_ASSERT(in46a_from_eua(&eua, &ia) < 0);
+	OSMO_ASSERT(in46a_from_eua(&eua, ia) < 0);
 
 	/* unspecified V4 */
 	memcpy(eua.v, v4_unspec, sizeof(v4_unspec));
 	eua.l = sizeof(v4_unspec);
-	OSMO_ASSERT(in46a_from_eua(&eua, &ia) == 1);
-	OSMO_ASSERT(ia.len == 4);
-	OSMO_ASSERT(ia.v4.s_addr == 0);
+	OSMO_ASSERT(in46a_from_eua(&eua, ia) == 1);
+	OSMO_ASSERT(ia[0].len == 4);
+	OSMO_ASSERT(ia[0].v4.s_addr == 0);
 
 	/* specified V4 */
 	memcpy(eua.v, v4_spec, sizeof(v4_spec));
 	eua.l = sizeof(v4_spec);
-	OSMO_ASSERT(in46a_from_eua(&eua, &ia) == 1);
-	OSMO_ASSERT(ia.len == 4);
-	OSMO_ASSERT(ia.v4.s_addr == htonl(0x01020304));
+	OSMO_ASSERT(in46a_from_eua(&eua, ia) == 1);
+	OSMO_ASSERT(ia[0].len == 4);
+	OSMO_ASSERT(ia[0].v4.s_addr == htonl(0x01020304));
 }
 
 static void test_in46a_netmasklen(void)
@@ -318,7 +318,7 @@ static void test_in46a_to_eua_v4v6() {
 
 static void test_in46a_from_eua_v6(void)
 {
-	struct in46_addr ia;
+	struct in46_addr ia[2];
 	struct ul66_t eua;
 	const uint8_t v6_unspec[] = { PDP_EUA_ORG_IETF, PDP_EUA_TYPE_v6 };
 	const uint8_t v6_spec[] = { PDP_EUA_ORG_IETF, PDP_EUA_TYPE_v6,
@@ -331,16 +331,16 @@ static void test_in46a_from_eua_v6(void)
 	/* unspecified V6 */
 	memcpy(eua.v, v6_unspec, sizeof(v6_unspec));
 	eua.l = sizeof(v6_unspec);
-	OSMO_ASSERT(in46a_from_eua(&eua, &ia) == 1);
-	OSMO_ASSERT(ia.len == 16);
-	OSMO_ASSERT(IN6_IS_ADDR_UNSPECIFIED(&ia.v6));
+	OSMO_ASSERT(in46a_from_eua(&eua, ia) == 1);
+	OSMO_ASSERT(ia[0].len == 16);
+	OSMO_ASSERT(IN6_IS_ADDR_UNSPECIFIED(&ia[0].v6));
 
 	/* specified V6 */
 	memcpy(eua.v, v6_spec, sizeof(v6_spec));
 	eua.l = sizeof(v6_spec);
-	OSMO_ASSERT(in46a_from_eua(&eua, &ia) == 1);
-	OSMO_ASSERT(ia.len == 16);
-	OSMO_ASSERT(!memcmp(&ia.v6, v6_spec+2, ia.len));
+	OSMO_ASSERT(in46a_from_eua(&eua, ia) == 1);
+	OSMO_ASSERT(ia[0].len == 16);
+	OSMO_ASSERT(!memcmp(&ia[0].v6, v6_spec+2, ia[0].len));
 }
 
 static void test_in46a_from_eua_v4v6(void) {