drm_hwcomposer: Simplify DrmHwcTwo::GetDisplay()

Cosmetic change: make GetDisplay() non-static class method + use
deduced return type.

Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>

hwc2_device/DrmHwcTwo.h

@@ -37,14 +37,6 @@ class DrmHwcTwo {
 #endif
   std::pair<HWC2_PFN_REFRESH, hwc2_callback_data_t> refresh_callback_{};
 
-  static HwcDisplay *GetDisplay(DrmHwcTwo *hwc, hwc2_display_t display_handle) {
-    auto it = hwc->displays_.find(display_handle);
-    if (it == hwc->displays_.end())
-      return nullptr;
-
-    return &it->second;
-  }
-
   // Device functions
   HWC2::Error CreateVirtualDisplay(uint32_t width, uint32_t height,
                                    int32_t *format, hwc2_display_t *display);
@@ -55,6 +47,11 @@ class DrmHwcTwo {
                                hwc2_function_pointer_t function);
   HWC2::Error CreateDisplay(hwc2_display_t displ, HWC2::DisplayType type);
 
+  auto GetDisplay(hwc2_display_t display_handle) {
+    return displays_.count(display_handle) != 0 ? &displays_.at(display_handle)
+                                                : nullptr;
+  }
+
   auto &GetResMan() {
     return resource_manager_;
   }

hwc2_device/hwc2_device.cpp

@@ -74,8 +74,8 @@ static int32_t DisplayHook(hwc2_device_t *dev, hwc2_display_t display_handle,
         GetFuncName(__PRETTY_FUNCTION__).c_str());
   DrmHwcTwo *hwc = ToDrmHwcTwo(dev);
   const std::lock_guard<std::mutex> lock(hwc->GetResMan().GetMainLock());
-  HwcDisplay *display = DrmHwcTwo::GetDisplay(hwc, display_handle);
-  if (!display)
+  auto *display = hwc->GetDisplay(display_handle);
+  if (display == nullptr)
     return static_cast<int32_t>(HWC2::Error::BadDisplay);
 
   return static_cast<int32_t>((display->*func)(std::forward<Args>(args)...));
@@ -88,8 +88,8 @@ static int32_t LayerHook(hwc2_device_t *dev, hwc2_display_t display_handle,
         layer_handle, GetFuncName(__PRETTY_FUNCTION__).c_str());
   DrmHwcTwo *hwc = ToDrmHwcTwo(dev);
   const std::lock_guard<std::mutex> lock(hwc->GetResMan().GetMainLock());
-  HwcDisplay *display = DrmHwcTwo::GetDisplay(hwc, display_handle);
-  if (!display)
+  auto *display = hwc->GetDisplay(display_handle);
+  if (display == nullptr)
     return static_cast<int32_t>(HWC2::Error::BadDisplay);
 
   HwcLayer *layer = display->get_layer(layer_handle);