libobs-d3d11: Consistent exception catch parameters

Fixed missing references, and stray usages of const references instead
of reference to const types. Apply const correctly where applicable.

libobs-d3d11/d3d11-rebuild.cpp

@@ -440,6 +440,6 @@ try {
 } catch (const char *error) {
 	bcrash("Failed to recreate D3D11: %s", error);
 
-} catch (HRError &error) {
+} catch (const HRError &error) {
 	bcrash("Failed to recreate D3D11: %s (%08lX)", error.str, error.hr);
 }