Add test for hostname getter

Signed-off-by: Pengyu Lv <pengyu.lv@arm.com>
diff --git a/tests/suites/test_suite_ssl.function b/tests/suites/test_suite_ssl.function
index d3eecce..5f53d87 100644
--- a/tests/suites/test_suite_ssl.function
+++ b/tests/suites/test_suite_ssl.function
@@ -1148,13 +1148,19 @@
 /* BEGIN_CASE depends_on:MBEDTLS_SSL_HANDSHAKE_WITH_CERT_ENABLED */
 void ssl_set_hostname_twice(char *hostname0, char *hostname1)
 {
+    const char *hostname;
     mbedtls_ssl_context ssl;
 
     mbedtls_ssl_init(&ssl);
     USE_PSA_INIT();
 
     TEST_ASSERT(mbedtls_ssl_set_hostname(&ssl, hostname0) == 0);
+    hostname = mbedtls_ssl_get_hostname(&ssl);
+    TEST_ASSERT(strcmp(hostname0, hostname) == 0);
+
     TEST_ASSERT(mbedtls_ssl_set_hostname(&ssl, hostname1) == 0);
+    hostname = mbedtls_ssl_get_hostname(&ssl);
+    TEST_ASSERT(strcmp(hostname1, hostname) == 0);
 
 exit:
     mbedtls_ssl_free(&ssl);