Use canonical UniquePtr.h header

Change-Id: Iab1dc428c2330a07a5944a1cfbb25c8134b11950
diff --git a/keystore-engine/ecdsa_meth.cpp b/keystore-engine/ecdsa_meth.cpp
index 7b673a2..a059b54 100644
--- a/keystore-engine/ecdsa_meth.cpp
+++ b/keystore-engine/ecdsa_meth.cpp
@@ -23,7 +23,7 @@
  *
  */
 
-#include <utils/UniquePtr.h>
+#include <UniquePtr.h>
 
 //#define LOG_NDEBUG 0
 #define LOG_TAG "OpenSSL-keystore-ecdsa"