Fix potential free of uninitialised pointer

A test was added in that could cause a jump to exit prior to
initialisation of a pointer that would get freed if that test failed.

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
diff --git a/tests/suites/test_suite_rsa.function b/tests/suites/test_suite_rsa.function
index f5f4aac..f5f5159 100644
--- a/tests/suites/test_suite_rsa.function
+++ b/tests/suites/test_suite_rsa.function
@@ -179,11 +179,12 @@
     mbedtls_test_rnd_pseudo_info rnd_info;
 
     mbedtls_rsa_init( &ctx );
-    TEST_ASSERT( mbedtls_rsa_set_padding( &ctx, padding_mode,
-                                          MBEDTLS_MD_NONE ) == 0 );
     mbedtls_mpi_init( &N ); mbedtls_mpi_init( &P );
     mbedtls_mpi_init( &Q ); mbedtls_mpi_init( &E );
 
+    TEST_ASSERT( mbedtls_rsa_set_padding( &ctx, padding_mode,
+                                          MBEDTLS_MD_NONE ) == 0 );
+
     memset( output, 0x00, sizeof( output ) );
     memset( &rnd_info, 0, sizeof( mbedtls_test_rnd_pseudo_info ) );