iommu/tegra241-cmdqv: Staticize cmdqv_debugfs_dir

Fix a sparse warning.

Fixes: 918eb5c ("iommu/arm-smmu-v3: Add in-kernel support for NVIDIA Tegra241 (Grace) CMDQV")
Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Signed-off-by: Nicolin Chen <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>

Author: nicolinc

drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c

@@ -800,7 +800,7 @@ static int tegra241_cmdqv_init_structures(struct arm_smmu_device *smmu)
 	return 0;
 }
 
-struct dentry *cmdqv_debugfs_dir;
+static struct dentry *cmdqv_debugfs_dir;
 
 static struct arm_smmu_device *
 __tegra241_cmdqv_probe(struct arm_smmu_device *smmu, struct resource *res,