tls13: srv: rename mbedtls_ssl_tls13_check_kex_modes

The function is renamed to
`mbedtls_ssl_tls13_is_kex_mode_supported` and
the behaviour is reversed.

Signed-off-by: Pengyu Lv <pengyu.lv@arm.com>
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index e362ebd..1439ca0 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -1941,49 +1941,49 @@
     defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED)
 /**
  * Given a list of key exchange modes, check if at least one of them is
- * supported.
+ * supported by peer.
  *
  * \param[in] ssl  SSL context
  * \param kex_modes_mask  Mask of the key exchange modes to check
  *
- * \return 0 if at least one of the key exchange modes is supported,
- *         !=0 otherwise.
+ * \return True, if at least one of the key exchange modes is supported,
+ *         False, otherwise.
  */
-static inline unsigned mbedtls_ssl_tls13_check_kex_modes(mbedtls_ssl_context *ssl,
-                                                         int kex_modes_mask)
+static inline int mbedtls_ssl_tls13_is_kex_mode_supported(mbedtls_ssl_context *ssl,
+                                                          int kex_modes_mask)
 {
-    return (ssl->handshake->tls13_kex_modes & kex_modes_mask) == 0;
+    return (ssl->handshake->tls13_kex_modes & kex_modes_mask) != 0;
 }
 
 static inline int mbedtls_ssl_tls13_psk_enabled(mbedtls_ssl_context *ssl)
 {
-    return !mbedtls_ssl_tls13_check_kex_modes(ssl,
-                                              MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK);
+    return mbedtls_ssl_tls13_is_kex_mode_supported(ssl,
+                                                   MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK);
 }
 
 static inline int mbedtls_ssl_tls13_psk_ephemeral_enabled(
     mbedtls_ssl_context *ssl)
 {
-    return !mbedtls_ssl_tls13_check_kex_modes(ssl,
-                                              MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL);
+    return mbedtls_ssl_tls13_is_kex_mode_supported(ssl,
+                                                   MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL);
 }
 
 static inline int mbedtls_ssl_tls13_ephemeral_enabled(mbedtls_ssl_context *ssl)
 {
-    return !mbedtls_ssl_tls13_check_kex_modes(ssl,
-                                              MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL);
+    return mbedtls_ssl_tls13_is_kex_mode_supported(ssl,
+                                                   MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL);
 }
 
 static inline int mbedtls_ssl_tls13_some_ephemeral_enabled(mbedtls_ssl_context *ssl)
 {
-    return !mbedtls_ssl_tls13_check_kex_modes(ssl,
-                                              MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ALL);
+    return mbedtls_ssl_tls13_is_kex_mode_supported(ssl,
+                                                   MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ALL);
 }
 
 static inline int mbedtls_ssl_tls13_some_psk_enabled(mbedtls_ssl_context *ssl)
 {
-    return !mbedtls_ssl_tls13_check_kex_modes(ssl,
-                                              MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ALL);
+    return mbedtls_ssl_tls13_is_kex_mode_supported(ssl,
+                                                   MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ALL);
 }
 #endif /* MBEDTLS_SSL_SRV_C &&
           MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED */