[PATCH] iommu/mediatek: fix NULL pointer dereference when printing dev_name

[Miles Chen]

>Hi Miles,
>
>Thank you for the patch! Perhaps something to improve:
>
>[auto build test WARNING on joro-iommu/next]
>[also build test WARNING on v5.18-rc3 next-20220422]
>[If your patch is applied to the wrong git tree, kindly drop us a note.
>And when submitting patch, we suggest to use '--base' as documented in
>https://git-scm.com/docs/git-format-patch]
>
>url:    https://github.com/intel-lab-lkp/linux/commits/Miles-Chen/iommu-mediatek-fix-NULL-pointer-dereference-when-printing-dev_name/20220423-070605
>base:   https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git next
>config: hexagon-randconfig-r041-20220422 (https://download.01.org/0day-ci/archive/20220423/202204231446.IYKdZ674-lkp@intel.com/config)
>compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 5bd87350a5ae429baf8f373cb226a57b62f87280)
>reproduce (this is a W=1 build):
>        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>        chmod +x ~/bin/make.cross
>        # https://github.com/intel-lab-lkp/linux/commit/85771767e503ca60069fe4e6ec2ddb80c7f9bafa
>        git remote add linux-review https://github.com/intel-lab-lkp/linux
>        git fetch --no-tags linux-review Miles-Chen/iommu-mediatek-fix-NULL-pointer-dereference-when-printing-dev_name/20220423-070605
>        git checkout 85771767e503ca60069fe4e6ec2ddb80c7f9bafa
>        # save the config file
>        mkdir build_dir && cp config build_dir/.config
>        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash drivers/iommu/
>
>If you fix the issue, kindly add following tag as appropriate
>Reported-by: kernel test robot <lkp at intel.com>
>
>All warnings (new ones prefixed by >>):
>
>>> drivers/iommu/mtk_iommu.c:605:6: warning: variable 'larbdev' is uninitialized when used here [-Wuninitialized]
>           if (larbdev) {
>               ^~~~~~~
>   drivers/iommu/mtk_iommu.c:597:24: note: initialize the variable 'larbdev' to silence this warning
>           struct device *larbdev;
>                                 ^
>                                  = NULL
>   1 warning generated.

Thanks for catching this, I will fix this in next version.

thanks,
Miles