Bug 1328602 - Fix incorrect return type in ffi signature. r=gfx?

MozReview-Commit-ID: hbkWlWYkDP

gfx/webrender_bindings/webrender_ffi.h

@@ -203,7 +203,7 @@ wr_renderer_set_profiler_enabled(WrRenderer* renderer, bool enabled) WR_FUNC;
 WR_INLINE bool
 wr_renderer_current_epoch(WrRenderer* renderer, WrPipelineId pipeline_id, WrEpoch* out_epoch) WR_FUNC;
 
-WR_INLINE bool
+WR_INLINE void
 wr_renderer_delete(WrRenderer* renderer) WR_FUNC;
 
 WR_INLINE void