Unify memcmp functions

Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
diff --git a/library/rsa.c b/library/rsa.c
index 3f076f0..a387d09 100644
--- a/library/rsa.c
+++ b/library/rsa.c
@@ -1933,7 +1933,7 @@
     MBEDTLS_MPI_CHK( mbedtls_rsa_private( ctx, f_rng, p_rng, sig, sig_try ) );
     MBEDTLS_MPI_CHK( mbedtls_rsa_public( ctx, sig_try, verif ) );
 
-    if( mbedtls_safer_memcmp( verif, sig, ctx->len ) != 0 )
+    if( mbedtls_cf_memcmp( verif, sig, ctx->len ) != 0 )
     {
         ret = MBEDTLS_ERR_RSA_PRIVATE_FAILED;
         goto cleanup;
@@ -2231,8 +2231,8 @@
      * Compare
      */
 
-    if( ( ret = mbedtls_safer_memcmp( encoded, encoded_expected,
-                                      sig_len ) ) != 0 )
+    if( ( ret = mbedtls_cf_memcmp( encoded, encoded_expected,
+                                              sig_len ) ) != 0 )
     {
         ret = MBEDTLS_ERR_RSA_VERIFY_FAILED;
         goto cleanup;