Use free for memory chunks allocated through memalign.

BUG: 8234423
Change-Id: Ic4100a780908c94540722cc4af5f73f4940431b4
diff --git a/libs/hwui/TextDropShadowCache.cpp b/libs/hwui/TextDropShadowCache.cpp
index db7bd48..f1f35bd 100644
--- a/libs/hwui/TextDropShadowCache.cpp
+++ b/libs/hwui/TextDropShadowCache.cpp
@@ -222,7 +222,7 @@
         }
 
         // Cleanup shadow
-        delete shadow.image;
+        free(shadow.image);
     }
 
     return texture;