msi: Initialize string pointer to NULL

[Kirill K. Smirnov]

Hi Nathan,
> -
>    haystack_table_name = NULL;
>   r = table->ops->get_column_info( table, i, &col_name, NULL,
>                                    NULL, &haystack_table_name );
>   if( r != ERROR_SUCCESS )

I'm afraid, but this patch silences valgrind only, but does not solves the 
problem. It seems to me, that if table->ops->get_column_info() succeeds, it 
initializes haystack_table_name, and if it fails, we do not use 
haystack_table_name at all (we immediately return from this function). Thus, 
the problem lies somewhere in get_column_info().

So it is useless (and harmful, because it confuses valgrind) to initialize it 
like this.

--
Kirill