target/ppc: Fix TCG leak with the evmwsmiaa instruction

target/ppc: Fix TCG leak with the evmwsmiaa instruction

Fix double-call to tcg_temp_new_i64(), where a temp is allocated both at
declaration time and further down the implementation of gen_evmwsmiaa().

Note that gen_evmwsmia() and gen_evmwsmiaa() are still not implemented
correctly, as they invoke gen_evmwsmi() which may return early, but the
return is not propagated. This will be fixed in my patch for bug #1888918.

Signed-off-by: Matthieu Bucchianeri <matthieu.bucchianeri@leostella.com>
Message-Id: <20200727172114.31415-1-matthieu.bucchianeri@leostella.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>