Adapt RSA verify failure code

RSA verification now returns MBEDTLS_ERR_RSA_VERIFY_FAILED where it
used to return MBEDTLS_ERR_RSA_INVALID_PADDING. Fix pk_rsa_match.

This ompletes the functional merge of:
* "Adapt test suites to modified error codes"
* "PK: support for opaque keys"
diff --git a/tests/suites/test_suite_pk.function b/tests/suites/test_suite_pk.function
index bd92f0c..943b3f2 100644
--- a/tests/suites/test_suite_pk.function
+++ b/tests/suites/test_suite_pk.function
@@ -128,7 +128,7 @@
                                         hash, sizeof hash, sig, sig_len - 1 ) == MBEDTLS_ERR_RSA_VERIFY_FAILED );
         sig[sig_len-1] ^= 1;
         TEST_ASSERT( mbedtls_pk_verify( tested_ctx, MBEDTLS_MD_NONE,
-                                        hash, sizeof hash, sig, sig_len ) == MBEDTLS_ERR_RSA_INVALID_PADDING );
+                                        hash, sizeof hash, sig, sig_len ) == MBEDTLS_ERR_RSA_VERIFY_FAILED );
     }
 
     /* Test encryption */