Remove radix arg from mbedtls_test_read_mpi

All uses have radix argument removed, using script.

Signed-off-by: Werner Lewis <werner.lewis@arm.com>
diff --git a/tests/suites/test_suite_x509write.function b/tests/suites/test_suite_x509write.function
index 6a9cfeb..d6879a2 100644
--- a/tests/suites/test_suite_x509write.function
+++ b/tests/suites/test_suite_x509write.function
@@ -248,7 +248,7 @@
     (void) rsa_alt;
 #endif
 
-    TEST_ASSERT( mbedtls_test_read_mpi( &serial, 10, serial_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &serial, serial_str ) == 0 );
 
     if( ver != -1 )
         mbedtls_x509write_crt_set_version( &crt, ver );