drm_hwcomposer: Fix incorrect modeset buffer size

Address developer error that grapped hdisplay for the height.

Change-Id: I2d40d01ede9239210ffa8acdb8f972bff285d144
Signed-off-by: Drew Davenport <ddavenport@google.com>
diff --git a/hwc2_device/HwcDisplay.cpp b/hwc2_device/HwcDisplay.cpp
index 716c33a..0503f39 100644
--- a/hwc2_device/HwcDisplay.cpp
+++ b/hwc2_device/HwcDisplay.cpp
@@ -193,7 +193,7 @@
   const HwcDisplayConfig *current_config = GetCurrentConfig();
 
   const uint32_t width = new_config->mode.GetRawMode().hdisplay;
-  const uint32_t height = new_config->mode.GetRawMode().hdisplay;
+  const uint32_t height = new_config->mode.GetRawMode().vdisplay;
 
   std::optional<LayerData> modeset_layer_data;
   // If a client layer has already been provided, and its size matches the