Mark static int SSL functions CHECK_RETURN_CRITICAL

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
diff --git a/library/ssl_ciphersuites.c b/library/ssl_ciphersuites.c
index 3826ad2..ceec77e 100644
--- a/library/ssl_ciphersuites.c
+++ b/library/ssl_ciphersuites.c
@@ -2181,6 +2181,7 @@
 static int supported_ciphersuites[MAX_CIPHERSUITES];
 static int supported_init = 0;
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ciphersuite_is_removed( const mbedtls_ssl_ciphersuite_t *cs_info )
 {
     (void)cs_info;