Fix check for nullptr surface IBinder

Bug: 146345307
Test: build, boot, libsurfaceflinger_unittest, SurfaceFlinger_test
Change-Id: I79d5bb71beb573c3c8a150c938aa6d7fa301353f
diff --git a/services/surfaceflinger/tests/unittests/TransactionApplicationTest.cpp b/services/surfaceflinger/tests/unittests/TransactionApplicationTest.cpp
index a465388..994a509 100644
--- a/services/surfaceflinger/tests/unittests/TransactionApplicationTest.cpp
+++ b/services/surfaceflinger/tests/unittests/TransactionApplicationTest.cpp
@@ -315,4 +315,9 @@
     BlockedByPriorTransaction(/*flags*/ 0, /*syncInputWindows*/ true);
 }
 
+TEST_F(TransactionApplicationTest, FromHandle) {
+    sp<IBinder> badHandle;
+    auto ret = mFlinger.fromHandle(badHandle);
+    EXPECT_EQ(nullptr, ret.get());
+}
 } // namespace android