powerpc/powernv: Check kzalloc() return value in pnv_pci_table_alloc

pnv_pci_table_alloc() ignores possible failure from kzalloc_node(),
this adds a check. There are 2 callers of pnv_pci_table_alloc(),
one already checks for tbl!=NULL, this adds WARN_ON() to the other path
which only happens during boot time in IODA1 and not expected to fail.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/powernv/pci-ioda.c

@@ -2151,6 +2151,9 @@ static void pnv_pci_ioda1_setup_dma_pe(struct pnv_phb *phb,
 
 found:
 	tbl = pnv_pci_table_alloc(phb->hose->node);
+	if (WARN_ON(!tbl))
+		return;
+
 	iommu_register_group(&pe->table_group, phb->hose->global_number,
 			pe->pe_number);
 	pnv_pci_link_table_and_group(phb->hose->node, 0, tbl, &pe->table_group);

arch/powerpc/platforms/powernv/pci.c

@@ -766,6 +766,9 @@ struct iommu_table *pnv_pci_table_alloc(int nid)
 	struct iommu_table *tbl;
 
 	tbl = kzalloc_node(sizeof(struct iommu_table), GFP_KERNEL, nid);
+	if (!tbl)
+		return NULL;
+
 	INIT_LIST_HEAD_RCU(&tbl->it_group_list);
 	kref_init(&tbl->it_kref);