target/*helper: don't check retaddr before calling cpu_restore_state

cpu_restore_state officially supports being passed an address it can't
resolve the state for. As a result the checks in the helpers are
superfluous and can be removed. This makes the code consistent with
other users of cpu_restore_state.

Of course this does nothing to address what to do if cpu_restore_state
can't resolve the state but so far it seems this is handled elsewhere.

The change was made with included coccinelle script.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
[rth: Fixed up comment indentation.  Added second hunk to script to
combine cpu_restore_state and cpu_loop_exit.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
