Get rid of most instance of 'foo != NULL'

core/src/fxcrt/fx_basic_plex.cpp

Index: core/src/fxcrt/fx_basic_plex.cpp
diff --git a/core/src/fxcrt/fx_basic_plex.cpp b/core/src/fxcrt/fx_basic_plex.cpp
index b6383ecf20ca705840a8ea5e224595f3e79c3c53..91cc1313bdf3b6bf1c6ae8e5df56422e9f019407 100644
--- a/core/src/fxcrt/fx_basic_plex.cpp
+++ b/core/src/fxcrt/fx_basic_plex.cpp
@@ -18,10 +18,9 @@ CFX_Plex* CFX_Plex::Create(CFX_Plex*& pHead,
 }
 void CFX_Plex::FreeDataChain() {
   CFX_Plex* p = this;
-  while (p != NULL) {
-    uint8_t* bytes = (uint8_t*)p;
-    CFX_Plex* pNext = p->pNext;
-    FX_Free(bytes);
-    p = pNext;
+  while (p) {
+    CFX_Plex* old = p;
+    p = p->pNext;
+    FX_Free(old);
   }
 }