scripts: twister: Fix serial_py referenced before assignment

This fixes `serial_py referenced before assignment` if `flash_before`
is set.

(cherry picked from commit 78f688a)

Original-Signed-off-by: Armin Kessler <ake@espros.com>
GitOrigin-RevId: 78f688a
Cr-Build-Id: 8732478031671813841
Cr-Build-Url: https://cr-buildbucket.appspot.com/build/8732478031671813841
Copybot-Job-Name: zephyr-main-copybot-downstream
Change-Id: I7fd0d843783f2d00085c9b999c498c8e7ffac89a
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/zephyr/+/5984633
Reviewed-by: Ting Shen <phoenixshen@chromium.org>
Commit-Queue: Ting Shen <phoenixshen@chromium.org>
Tested-by: ChromeOS Prod (Robot) <chromeos-ci-prod@chromeos-bot.iam.gserviceaccount.com>

scripts/pylib/twister/twisterlib/hardwaremap.py

@@ -258,14 +258,14 @@ def load(self, map_file):
             flash_with_test = dut.get('flash_with_test')
             if flash_with_test is None:
                 flash_with_test = self.options.device_flash_with_test
+            serial_pty = dut.get('serial_pty')
             flash_before = dut.get('flash_before')
             if flash_before is None:
                 flash_before = self.options.flash_before and (not (flash_with_test or serial_pty))
             platform  = dut.get('platform')
             id = dut.get('id')
             runner = dut.get('runner')
             runner_params = dut.get('runner_params')
-            serial_pty = dut.get('serial_pty')
             serial = dut.get('serial')
             baud = dut.get('baud', None)
             product = dut.get('product')