ta: pkcs11: correct RSA keys extended attributes sanitation

Fix RSA key attributes function load_tee_rsa_key_attrs() that badly
checks that the 5 extended RSA attributes are found in the key object.

Link: OP-TEE/optee_test#721 (comment)
Link: OP-TEE/optee_test#721 (comment)
Fixes: 0442c95 ("ta: pkcs11: Add support for RSA signing & verification")
Signed-off-by: Etienne Carriere <etienne.carriere@foss.st.com>

ta/pkcs11/src/processing_rsa.c

@@ -569,6 +569,8 @@ enum pkcs11_rc load_tee_rsa_key_attrs(TEE_Attribute **tee_attrs,
 			break;
 		}
 
+		rc = PKCS11_CKR_GENERAL_ERROR;
+
 		if (pkcs2tee_load_attr(&attrs[count], TEE_ATTR_RSA_PRIME1, obj,
 				       PKCS11_CKA_PRIME_1))
 			count++;