vdpau_wrapper: make initialization of library handles thread-safe
vdpau_wrapper: make initialization of library handles thread-safe

Reviewed-by: Aaron Plattner <7c39395e2e801146cdbd7fb4a41282e4f38db44e@nvidia.com>
Signed-off-by: Aaron Plattner <7c39395e2e801146cdbd7fb4a41282e4f38db44e@nvidia.com>

Distrotech/libvdpau,mosterta/libvdpau,Distrotech/libvdpau,mosterta/libvdpau,mosterta/libvdpau,Distrotech/libvdpau