Revert "Remove FX_Alloc() null checks now that it can't return NULL."

core/src/fxcrt/xml_int.h

Index: core/src/fxcrt/xml_int.h
diff --git a/core/src/fxcrt/xml_int.h b/core/src/fxcrt/xml_int.h
index f0a2485163aed673e0f41af4447b7f455c10ec26..964c7944d178024fe62de2565cb2b97f3b685b17 100644
--- a/core/src/fxcrt/xml_int.h
+++ b/core/src/fxcrt/xml_int.h
@@ -107,6 +107,9 @@ public:
         m_dwSize = (size_t)FX_MIN(FX_XMLDATASTREAM_BufferSize, nLength - m_nStart);
         if (!m_pBuffer) {
             m_pBuffer = FX_Alloc(FX_BYTE, m_dwSize);
+            if (!m_pBuffer) {
+                return FALSE;
+            }
         }
         return m_pFileRead->ReadBlock(m_pBuffer, m_nStart, m_dwSize);
     }