tcg: rename tb_find_physical()

tcg: rename tb_find_physical()

In fact, this function does not exactly perform a lookup by physical
address as it is descibed for comment on get_page_addr_code(). Thus
it may be a bit confusing to have "physical" in it's name. So rename it
to tb_htable_lookup() to better reflect its actual functionality.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Message-Id: <20160715175852.30749-13-sergey.fedorov@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>