Use canonical UniquePtr.h header

Change-Id: Iab1dc428c2330a07a5944a1cfbb25c8134b11950
diff --git a/softkeymaster/keymaster_openssl.cpp b/softkeymaster/keymaster_openssl.cpp
index 4aaaea2..79e2337 100644
--- a/softkeymaster/keymaster_openssl.cpp
+++ b/softkeymaster/keymaster_openssl.cpp
@@ -28,7 +28,7 @@
 #include <openssl/err.h>
 #include <openssl/x509.h>
 
-#include <utils/UniquePtr.h>
+#include <UniquePtr.h>
 
 // For debugging
 //#define LOG_NDEBUG 0