Move error_code.h into otautil.

This way it stops requiring relative path ".." in LOCAL_C_INCLUDES
(uncrypt and edify). Soong doesn't accept non-local ".." in
"local_include_dirs".

Test: mmma bootable/recovery
Change-Id: Ia4649789cef2aaeb2785483660e9ea5a8b389c62
diff --git a/uncrypt/Android.mk b/uncrypt/Android.mk
index a3b0ca9..601f927 100644
--- a/uncrypt/Android.mk
+++ b/uncrypt/Android.mk
@@ -17,10 +17,10 @@
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES := uncrypt.cpp
-LOCAL_C_INCLUDES := $(LOCAL_PATH)/..
 LOCAL_MODULE := uncrypt
 LOCAL_STATIC_LIBRARIES := \
     libbootloader_message \
+    libotautil \
     libbase \
     liblog \
     libfs_mgr \