Now that we have proper locking after MTTCG patches have landed, we
can revert the commit.  This reverts commit

a9353fe8.

CC: Peter Maydell <peter.maydell@linaro.org>
CC: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: NPranith Kumar <bobby.prani@gmail.com>
Message-Id: <20170712215143.19594-1-bobby.prani@gmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>