When moving this code out of probe_target_compiler(), we failed to adjust
the variable in which the target is located, resulting in e.g.
powerpc64-linux-user-linux-gnu-gcc-10

Fixes: cd362def ("tests/tcg: merge configure.sh back into main configure script")
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220728183901.1290113-1-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>