d2d1: Fix a crash in ID2D1DeviceContext if no target is set.
Fixes Country Siblings' crash on startup.
d2d_device_context_draw
doesn't accept D2D_TARGET_UNKNOWN
because render_target->target.bitmap->rtv
isn't reliably set when calling ID3D11DeviceContext1_OMSetRenderTargets
. Therefore, we check for that condition and return early.
Edited by Akihiro Sagawa