surfaceflinger: make mPrimaryDisplayOrientation static

The convention is to store configstore values in static variables.

Bug: 113041375
Test: take screenshot, rotate screen, screencap
Change-Id: I085178803bc897e3e9201fd10bd8731cc5b617c1
diff --git a/services/surfaceflinger/DisplayDevice.cpp b/services/surfaceflinger/DisplayDevice.cpp
index aab6c22..cd86f81 100644
--- a/services/surfaceflinger/DisplayDevice.cpp
+++ b/services/surfaceflinger/DisplayDevice.cpp
@@ -604,7 +604,7 @@
     // need to take care of primary display rotation for mGlobalTransform
     // for case if the panel is not installed aligned with device orientation
     if (mType == DisplayType::DISPLAY_PRIMARY) {
-        int primaryDisplayOrientation = mFlinger->getPrimaryDisplayOrientation();
+        int primaryDisplayOrientation = SurfaceFlinger::primaryDisplayOrientation;
         DisplayDevice::orientationToTransfrom(
                 (orientation + primaryDisplayOrientation) % (DisplayState::eOrientation270 + 1),
                 w, h, &R);