Update comments to match code

s/get_vdev_spec/make_root_vdev

The former doesn't exist anymore.

Sponsored by: iXsystems, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Ryan Moeller <ryan@freqlabs.com>
Closes openzfs#8759

cmd/zpool/zpool_main.c

@@ -785,7 +785,7 @@ add_prop_list_default(const char *propname, char *propval, nvlist_t **props,
  *	-P	Display full path for vdev name.
  *
  * Adds the given vdevs to 'pool'.  As with create, the bulk of this work is
- * handled by get_vdev_spec(), which constructs the nvlist needed to pass to
+ * handled by make_root_vdev(), which constructs the nvlist needed to pass to
  * libzfs.
  */
 int
@@ -883,7 +883,7 @@ zpool_do_add(int argc, char **argv)
 		}
 	}
 
-	/* pass off to get_vdev_spec for processing */
+	/* pass off to make_root_vdev for processing */
 	nvroot = make_root_vdev(zhp, props, force, !force, B_FALSE, dryrun,
 	    argc, argv);
 	if (nvroot == NULL) {
@@ -1232,9 +1232,9 @@ zpool_do_labelclear(int argc, char **argv)
  *	-O	Set fsproperty=value in the pool's root file system
  *
  * Creates the named pool according to the given vdev specification.  The
- * bulk of the vdev processing is done in get_vdev_spec() in zpool_vdev.c.  Once
- * we get the nvlist back from get_vdev_spec(), we either print out the contents
- * (if '-n' was specified), or pass it to libzfs to do the creation.
+ * bulk of the vdev processing is done in make_root_vdev() in zpool_vdev.c.
+ * Once we get the nvlist back from make_root_vdev(), we either print out the
+ * contents (if '-n' was specified), or pass it to libzfs to do the creation.
  */
 int
 zpool_do_create(int argc, char **argv)
@@ -1388,7 +1388,7 @@ zpool_do_create(int argc, char **argv)
 		goto errout;
 	}
 
-	/* pass off to get_vdev_spec for bulk processing */
+	/* pass off to make_root_vdev for bulk processing */
 	nvroot = make_root_vdev(NULL, props, force, !force, B_FALSE, dryrun,
 	    argc - 1, argv + 1);
 	if (nvroot == NULL)