Revert "GATT: Fix GATT error response for execute write"

This reverts commit 6c4e4e0e.

Reason for revert: This patch does not make Fluoride comply with BT Spec,
it just make a false assumption to pass a test case.

Change-Id: I023b7673c52522e7c1a318f5b9596ebb4fbc99ec