platform/mellanox: Add null pointer checks for devm_kasprintf()

devm_kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure.

Compile-tested only.

Fixes: 1a218d3 ("platform/mellanox: mlxbf-pmc: Add Mellanox BlueField PMC driver")
Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Suggested-by: Vadim Pasternak <vadimp@nvidia.com>
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Reviewed-by: Vadim Pasternak <vadimp@nvidia.com>
Link: https://lore.kernel.org/r/20231201055447.2356001-1-chentao@kylinos.cn
[ij: split the change into two]
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

Author: KunWuChan

drivers/platform/mellanox/mlxbf-pmc.c

@@ -1771,6 +1771,8 @@ static int mlxbf_pmc_init_perftype_counter(struct device *dev, int blk_num)
 	attr->dev_attr.show = mlxbf_pmc_event_list_show;
 	attr->nr = blk_num;
 	attr->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL, "event_list");
+	if (!attr->dev_attr.attr.name)
+		return -ENOMEM;
 	pmc->block[blk_num].block_attr[i] = &attr->dev_attr.attr;
 	attr = NULL;
 
@@ -1784,6 +1786,8 @@ static int mlxbf_pmc_init_perftype_counter(struct device *dev, int blk_num)
 		attr->nr = blk_num;
 		attr->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
 							  "enable");
+		if (!attr->dev_attr.attr.name)
+			return -ENOMEM;
 		pmc->block[blk_num].block_attr[++i] = &attr->dev_attr.attr;
 		attr = NULL;
 	}
@@ -1810,6 +1814,8 @@ static int mlxbf_pmc_init_perftype_counter(struct device *dev, int blk_num)
 		attr->nr = blk_num;
 		attr->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
 							  "counter%d", j);
+		if (!attr->dev_attr.attr.name)
+			return -ENOMEM;
 		pmc->block[blk_num].block_attr[++i] = &attr->dev_attr.attr;
 		attr = NULL;
 
@@ -1821,6 +1827,8 @@ static int mlxbf_pmc_init_perftype_counter(struct device *dev, int blk_num)
 		attr->nr = blk_num;
 		attr->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
 							  "event%d", j);
+		if (!attr->dev_attr.attr.name)
+			return -ENOMEM;
 		pmc->block[blk_num].block_attr[++i] = &attr->dev_attr.attr;
 		attr = NULL;
 	}
@@ -1853,6 +1861,8 @@ static int mlxbf_pmc_init_perftype_reg(struct device *dev, int blk_num)
 		attr->nr = blk_num;
 		attr->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
 							  events[j].evt_name);
+		if (!attr->dev_attr.attr.name)
+			return -ENOMEM;
 		pmc->block[blk_num].block_attr[i] = &attr->dev_attr.attr;
 		attr = NULL;
 		i++;
@@ -1882,6 +1892,8 @@ static int mlxbf_pmc_create_groups(struct device *dev, int blk_num)
 	pmc->block[blk_num].block_attr_grp.attrs = pmc->block[blk_num].block_attr;
 	pmc->block[blk_num].block_attr_grp.name = devm_kasprintf(
 		dev, GFP_KERNEL, pmc->block_name[blk_num]);
+	if (!pmc->block[blk_num].block_attr_grp.name)
+		return -ENOMEM;
 	pmc->groups[pmc->group_num] = &pmc->block[blk_num].block_attr_grp;
 	pmc->group_num++;