Fix transitive include.

Was relying on include from MQDescriptor.h

Test: pass
Change-Id: Ic3f24fea3875ed1f598b18e4a1fa05c226a86037
diff --git a/keystore-engine/keystore_backend_hidl.cpp b/keystore-engine/keystore_backend_hidl.cpp
index b00cf4e..9a84e67 100644
--- a/keystore-engine/keystore_backend_hidl.cpp
+++ b/keystore-engine/keystore_backend_hidl.cpp
@@ -23,6 +23,7 @@
 #include "keystore_backend_hidl.h"
 
 #include <android/system/wifi/keystore/1.0/IKeystore.h>
+#include <log/log.h>
 
 using android::hardware::hidl_vec;
 using android::hardware::Return;