"NULL !=" = NULL

R=reed@google.com

Author: bsalomon@google.com

Review URL: https://codereview.chromium.org/544233002
diff --git a/src/effects/SkAvoidXfermode.cpp b/src/effects/SkAvoidXfermode.cpp
index aae6ba5..b596bfd 100644
--- a/src/effects/SkAvoidXfermode.cpp
+++ b/src/effects/SkAvoidXfermode.cpp
@@ -108,7 +108,7 @@
         SkASSERT(d <= 256);
 
         if (d > 0) {
-            if (NULL != aa) {
+            if (aa) {
                 d = SkAlphaMul(d, Accurate255To256(*aa++));
                 if (0 == d) {
                     continue;
@@ -157,7 +157,7 @@
         SkASSERT(d <= 32);
 
         if (d > 0) {
-            if (NULL != aa) {
+            if (aa) {
                 d = SkAlphaMul(d, Accurate255To256(*aa++));
                 if (0 == d) {
                     continue;