arm64: mm: Cleanup in pbha_bit0_pte_range

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I96IZH



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Remove unused variable.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202403141207.Ix7wfVox-lkp@intel.com/


Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>