Change signature of `mbedtls_rsa_deduce_private`

Make input arguments constant and adapt the implementation to use a temporary instead of in-place operations.
diff --git a/tests/suites/test_suite_rsa.function b/tests/suites/test_suite_rsa.function
index 062b971..f321554 100644
--- a/tests/suites/test_suite_rsa.function
+++ b/tests/suites/test_suite_rsa.function
@@ -804,7 +804,7 @@
     }
 
     /* Try to deduce D from N, P, Q, E. */
-    TEST_ASSERT( mbedtls_rsa_deduce_private( &P, &Q, &D, &E ) == result );
+    TEST_ASSERT( mbedtls_rsa_deduce_private( &P, &Q, &E, &D ) == result );
 
     if( !corrupt )
     {