msi: Prevent call to memset with a nullptr in get_tablecolumns function

[Hans Leidekker]

On Sun, 2014-05-18 at 13:27 -0400, Daniel Beitler wrote:
> This is a fix for bug #36139.
> 
> It looks like calling memset with a nullptr is undefined behavior. Gcc 
> 4.9 will actually optimize out the "if(colinfo)" condition if memset was 
> called on colinfo before.
> 
> 
> ---
>   dlls/msi/table.c | 7 +++++--
>   1 file changed, 5 insertions(+), 2 deletions(-)

Looks good, thanks.