iommu/io-pgtable-arm-v7s: Add error handle for page table allocation failure

In __arm_v7s_alloc_table function:
iommu call kmem_cache_alloc to allocate page table, this function
allocate memory may fail, when kmem_cache_alloc fails to allocate
table, call virt_to_phys will be abnomal and return unexpected phys
and goto out_free, then call kmem_cache_free to release table will
trigger KE, __get_free_pages and free_pages have similar problem,
so add error handle for page table allocation failure.

Fixes: 29859aeb ("iommu/io-pgtable-arm-v7s: Abort allocation when table address overflows the PTE")
Signed-off-by: Yunfei Wang <yf.wang@mediatek.com>
Cc: <stable@vger.kernel.org> # 5.10.*
Acked-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20211207113315.29109-1-yf.wang@mediatek.com


Signed-off-by: Will Deacon <will@kernel.org>