drm_hwcomposer: Remove redundant function from DrmHwcThree

The function implementation turned into simply removing a display from
the displays_ map, and is only called in one place. Remove it.

Change-Id: Ib8ab633b390cf6dd3e5ae4475201783dfecc82df
Signed-off-by: Drew Davenport <ddavenport@chromium.org>
Signed-off-by: Drew Davenport <ddavenport@google.com>
diff --git a/hwc3/DrmHwcThree.cpp b/hwc3/DrmHwcThree.cpp
index 54dba67..0adecf4 100644
--- a/hwc3/DrmHwcThree.cpp
+++ b/hwc3/DrmHwcThree.cpp
@@ -64,15 +64,6 @@
   composer_callback_->onHotplug(static_cast<int64_t>(display_id), connected);
 }
 
-void DrmHwcThree::RemoveDisplay(uint64_t display_id) {
-  DEBUG_FUNC();
-  HwcDisplay* display = GetDisplay(display_id);
-  if (display == nullptr) {
-    return;
-  }
-  Displays().erase(display_id);
-}
-
 void DrmHwcThree::CleanDisplayResources(uint64_t display_id) {
   DEBUG_FUNC();
   HwcDisplay* display = GetDisplay(display_id);
@@ -123,7 +114,7 @@
   DEBUG_FUNC();
   if (!connected) {
     composer_resources_->RemoveDisplay(display_id);
-    RemoveDisplay(display_id);
+    Displays().erase(display_id);
     return;
   }
 
@@ -131,7 +122,7 @@
     /* Cleanup existing display resources */
     CleanDisplayResources(display_id);
     composer_resources_->RemoveDisplay(display_id);
-    RemoveDisplay(display_id);
+    Displays().erase(display_id);
   }
   composer_resources_->AddPhysicalDisplay(display_id);
 }