Fix various typos

Correct an assortment of typos throughout the code base.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Closes #11774

include/sys/vdev_draid.h

@@ -51,7 +51,7 @@ extern "C" {
  * dRAID permutation map.
  */
 typedef struct draid_map {
-	uint64_t dm_children;	/* # of permuation columns */
+	uint64_t dm_children;	/* # of permutation columns */
 	uint64_t dm_nperms;	/* # of permutation rows */
 	uint64_t dm_seed;	/* dRAID map seed */
 	uint64_t dm_checksum;	/* Checksum of generated map */

include/sys/vdev_impl.h

@@ -501,7 +501,7 @@ typedef enum vbe_vers {
 	 * and is protected by an embedded checksum. By default, GRUB will
 	 * check if the boot filesystem supports storing the environment data
 	 * in a special location, and if so, will invoke filesystem specific
-	 * logic to retrieve it. This can be overriden by a variable, should
+	 * logic to retrieve it. This can be overridden by a variable, should
 	 * the user so desire.
 	 */
 	VB_RAW = 0,

include/sys/vdev_rebuild.h

@@ -60,7 +60,7 @@ typedef struct vdev_rebuild_phys {
 /*
  * The vdev_rebuild_t describes the current state and how a top-level vdev
  * should be rebuilt.  The core elements are the top-vdev, the metaslab being
- * rebuilt, range tree containing the allocted extents and the on-disk state.
+ * rebuilt, range tree containing the allocated extents and the on-disk state.
  */
 typedef struct vdev_rebuild {
 	vdev_t		*vr_top_vdev;		/* top-level vdev to rebuild */