Prevent free of uninitialised variables

In an error case it was possible for mbedtls_mpi variables to be free'd
uninitialised.

Signed-off-by: Paul Elliott <[email protected]>

tests/suites/test_suite_pk.function

@@ -723,6 +723,8 @@ void pk_rsa_encrypt_decrypt_test( data_t * message, int mod, int radix_P,
     size_t olen, rlen;
 
     mbedtls_pk_init( &pk );
+    mbedtls_mpi_init( &N ); mbedtls_mpi_init( &P );
+    mbedtls_mpi_init( &Q ); mbedtls_mpi_init( &E );
 
     memset( &rnd_info,  0, sizeof( mbedtls_test_rnd_pseudo_info ) );
     memset( output,     0, sizeof( output ) );