MSVC: resolve confusion about Mask type
MSVC: resolve confusion about Mask type

MSVC thinks I meant Vc::Mask<T, Abi>. But what I really meant was the
Mask member type of Vector. All other C++ compilers understood this...

Signed-off-by: Matthias Kretz <372ea4eca737a13cd010ee806d4ce7b98ee71550@kde.org>

VcDevel/Vc,chr-engwer/Vc,VcDevel/Vc,VcDevel/Vc,chr-engwer/Vc,chr-engwer/Vc,VcDevel/Vc