nvdimm/namespace: fix kernel-doc for function params

Adjust kernel-doc notation to prevent warnings when using -Wall.

namespace_devs.c:76: warning: No description found for return value of 'nd_is_uuid_unique'
namespace_devs.c:343: warning: No description found for return value of 'shrink_dpa_allocation'
namespace_devs.c:668: warning: No description found for return value of 'grow_dpa_allocation'
namespace_devs.c:958: warning: No description found for return value of 'namespace_update_uuid'
namespace_devs.c:1665: warning: Function parameter or member 'nd_mapping' not described in 'create_namespace_pmem'
namespace_devs.c:1665: warning: Excess function parameter 'nspm' description in 'create_namespace_pmem'
namespace_devs.c:1665: warning: No description found for return value of 'create_namespace_pmem'

[iweiny: s/-errno/ERR_PTR(-errno)/]

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc:  <nvdimm@lists.linux.dev>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20231207210545.24056-3-rdunlap@infradead.org
Signed-off-by: Ira Weiny <ira.weiny@intel.com>

Author: rddunlap

drivers/nvdimm/namespace_devs.c

@@ -71,6 +71,8 @@ static int is_namespace_uuid_busy(struct device *dev, void *data)
  * nd_is_uuid_unique - verify that no other namespace has @uuid
  * @dev: any device on a nvdimm_bus
  * @uuid: uuid to check
+ *
+ * Returns: %true if the uuid is unique, %false if not
  */
 bool nd_is_uuid_unique(struct device *dev, uuid_t *uuid)
 {
@@ -337,6 +339,8 @@ static int scan_free(struct nd_region *nd_region,
  * adjust_resource() the allocation to @n, but if @n is larger than the
  * allocation delete it and find the 'new' last allocation in the label
  * set.
+ *
+ * Returns: %0 on success on -errno on error
  */
 static int shrink_dpa_allocation(struct nd_region *nd_region,
 		struct nd_label_id *label_id, resource_size_t n)
@@ -662,6 +666,8 @@ void release_free_pmem(struct nvdimm_bus *nvdimm_bus,
  * allocations from the start of an interleave set and end at the first
  * BLK allocation or the end of the interleave set, whichever comes
  * first.
+ *
+ * Returns: %0 on success on -errno on error
  */
 static int grow_dpa_allocation(struct nd_region *nd_region,
 		struct nd_label_id *label_id, resource_size_t n)
@@ -951,6 +957,8 @@ static ssize_t uuid_show(struct device *dev, struct device_attribute *attr,
  * @dev: namespace type for generating label_id
  * @new_uuid: incoming uuid
  * @old_uuid: reference to the uuid storage location in the namespace object
+ *
+ * Returns: %0 on success on -errno on error
  */
 static int namespace_update_uuid(struct nd_region *nd_region,
 				 struct device *dev, uuid_t *new_uuid,
@@ -1656,8 +1664,10 @@ static int select_pmem_id(struct nd_region *nd_region, const uuid_t *pmem_id)
 /**
  * create_namespace_pmem - validate interleave set labelling, retrieve label0
  * @nd_region: region with mappings to validate
- * @nspm: target namespace to create
+ * @nd_mapping: container of dpa-resource-root + labels
  * @nd_label: target pmem namespace label to evaluate
+ *
+ * Returns: the created &struct device on success or ERR_PTR(-errno) on error
  */
 static struct device *create_namespace_pmem(struct nd_region *nd_region,
 					    struct nd_mapping *nd_mapping,