comcat: Fix mixing of HRESULT and LSTATUS types in COMCAT_CLSID_IEnumGUID_Next, COMCAT_IEnumCATEGORYINFO_Next and COMCAT_CATID_IEnumGUID_Next.

(Found by PreFast.)

The comparison should be (D3D_OK == hr && myDevice), not (D3D_OK == (hr && myDevice)).
(Found with PreFast.)

(Found by PreFast.)

It is only used for storing the result of RegEnumKeyW so it should be
LSTATUS instead of HRESULT.

(Found by PreFast.)

The comparison should be (D3D_OK == hr && myDevice), not (D3D_OK == (hr && myDevice)).
(Found with PreFast.)

Therefore fix the code to handle SetPropW failing with this in mind.
(Found by PreFast.)

Some versions of ole32 don't test that the lindex field of the
FORMATETC structure passed into functions is valid.

As a window being registered for drag and drop is a system-global
property, the tests could be affected by other processes in the
system.