Revert "[reboiot-cause] Fix a broken symlink of previous-reboot-cause…

… file removal issue (#10751)" (#10849)

This reverts commit dee7655.

Co-authored-by: Ubuntu <lizhuhua@lh-dev-vm-01.ziurp3vhri5utcxng1kcl2l1qa.xx.internal.cloudapp.net>

src/sonic-host-services/scripts/determine-reboot-cause

@@ -174,7 +174,7 @@ def main():
         os.makedirs(REBOOT_CAUSE_DIR)
 
     # Remove stale PREVIOUS_REBOOT_CAUSE_FILE if it exists
-    if os.path.exists(PREVIOUS_REBOOT_CAUSE_FILE) or os.path.islink(PREVIOUS_REBOOT_CAUSE_FILE):
+    if os.path.exists(PREVIOUS_REBOOT_CAUSE_FILE):
         os.remove(PREVIOUS_REBOOT_CAUSE_FILE)
 
     # This variable is kept for future-use purpose. When proc_cmd_line/vendor/software provides