Fix breakage from merge conflict related to deleteTestingOnlyBackendTexture sig. change

Change-Id: I28c50efb9c7723df19041640809994bff8ea5041
Reviewed-on: https://skia-review.googlesource.com/113421
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/tests/PromiseImageTest.cpp b/tests/PromiseImageTest.cpp
index b475147..4ba011b 100644
--- a/tests/PromiseImageTest.cpp
+++ b/tests/PromiseImageTest.cpp
@@ -197,7 +197,7 @@
                                                              true,
                                                              reporter));
 
-    gpu->deleteTestingOnlyBackendTexture(&backendTex);
+    gpu->deleteTestingOnlyBackendTexture(backendTex);
 }
 
 #endif