migration-test: ppc64: fix FORTH test program

Commit e51e711b has moved the initialization of start_address and
end_address after the definition of the command line argument,
where the nvramrc is initialized, and thus the loop is between 0 and 0
rather than 1 MiB and 100 MiB.

It doesn't affect the result of the test if all the tests are run in
sequence because the two first tests don't run the loop, so the
values are correctly initialized when we actually need them.

But it hangs when we ask to run only one test, for instance:

    QTEST_QEMU_BINARY=ppc64-softmmu/qemu-system-ppc64 \
    tests/migration-test -m=quick -p /ppc64/migration/validate_uuid_error

Fixes: e51e711b ("tests/migration: Add migration-test header file")
Cc: wei@redhat.com
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Message-Id: <20200107163437.52139-1-lvivier@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Acked-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NThomas Huth <thuth@redhat.com>

tests/qtest/migration-test.c

@@ -480,14 +480,14 @@ static int test_migrate_start(QTestState **from, QTestState **to,
     } else if (strcmp(arch, "ppc64") == 0) {
         machine_opts = "vsmt=8";
         memory_size = "256M";
+        start_address = PPC_TEST_MEM_START;
+        end_address = PPC_TEST_MEM_END;
         arch_source = g_strdup_printf("-nodefaults "
                                       "-prom-env 'use-nvramrc?=true' -prom-env "
                                       "'nvramrc=hex .\" _\" begin %x %x "
                                       "do i c@ 1 + i c! 1000 +loop .\" B\" 0 "
                                       "until'", end_address, start_address);
         arch_target = g_strdup("");
-        start_address = PPC_TEST_MEM_START;
-        end_address = PPC_TEST_MEM_END;
     } else if (strcmp(arch, "aarch64") == 0) {
         init_bootfile(bootpath, aarch64_kernel, sizeof(aarch64_kernel));
         machine_opts = "virt,gic-version=max";