fix funky formatting in SkNVRefCnt

BUG=skia:
TBR=reed@google.com
No API change.

Review URL: https://codereview.chromium.org/1505023002
diff --git a/include/core/SkRefCnt.h b/include/core/SkRefCnt.h
index 0e8d857..9d1e5f1 100644
--- a/include/core/SkRefCnt.h
+++ b/include/core/SkRefCnt.h
@@ -218,7 +218,7 @@
     void  unref() const {
         if (1 == sk_atomic_fetch_add(&fRefCnt, -1, sk_memory_order_acq_rel)) {
             SkDEBUGCODE(fRefCnt = 1;)  // restore the 1 for our destructor's assert
-                    delete (const Derived*)this;
+            delete (const Derived*)this;
         }
     }
     void  deref() const { this->unref(); }