doc: fix remaining Doxygen warnings

Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: Ic8aa4d5b8c1edff6875bba38fa5936a6fb9950cb

Reviewed-on: https://review.gerrithub.io/415871
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>

include/spdk/bdev_module.h

@@ -413,7 +413,10 @@ struct spdk_bdev_io {
 	/** It may be used by modules to put the bdev_io into its own list. */
 	TAILQ_ENTRY(spdk_bdev_io) module_link;
 
-	struct {
+	/** Fields that are used internally by the bdev subsystem.  Bdev modules
+	 *  must not read or write to these fields.
+	 */
+	struct __bdev_io_internal_fields {
 		/** Entry to the list need_buf of struct spdk_bdev. */
 		STAILQ_ENTRY(spdk_bdev_io) buf_link;
 	} internal;

include/spdk/nvme.h

@@ -1462,7 +1462,7 @@ int spdk_nvme_ns_cmd_read_with_md(struct spdk_nvme_ns *ns, struct spdk_nvme_qpai
  *        deallocate, which is often referred to as TRIM or UNMAP.
  *
  * \param ns NVMe namespace to submit the DSM request
- * \param type A bit field constructed from \ref enum spdk_nvme_dsm_attribute.
+ * \param type A bit field constructed from \ref spdk_nvme_dsm_attribute.
  * \param qpair I/O queue pair to submit the request
  * \param ranges An array of \ref spdk_nvme_dsm_range elements describing
  *		 the LBAs to operate on.

include/spdk/nvme_spec.h

@@ -813,6 +813,7 @@ enum spdk_nvme_feat {
 	/* 0xC0-0xFF - vendor specific */
 };
 
+/** Bit set of attributes for DATASET MANAGEMENT commands. */
 enum spdk_nvme_dsm_attribute {
 	SPDK_NVME_DSM_ATTR_INTEGRAL_READ		= 0x1,
 	SPDK_NVME_DSM_ATTR_INTEGRAL_WRITE		= 0x2,