Fix typos

Correct various typos in the comments and tests.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Closes #10423

include/sys/btree.h

@@ -47,7 +47,7 @@ extern "C" {
  * at its children. Leaf nodes only contain data elements, and form the bottom
  * layer of the tree. Unlike B+ Trees, in this B-Tree implementation the
  * elements in the core nodes are not copies of or references to leaf node
- * elements.  Each element occcurs only once in the tree, no matter what kind
+ * elements.  Each element occurs only once in the tree, no matter what kind
  * of node it is in.
  *
  * The tree's height is the same throughout, unlike many other forms of search

include/sys/zfs_ioctl.h

@@ -361,7 +361,7 @@ typedef struct dmu_replay_record {
 		} drr_redact;
 
 		/*
-		 * Nore: drr_checksum is overlaid with all record types
+		 * Note: drr_checksum is overlaid with all record types
 		 * except DRR_BEGIN.  Therefore its (non-pad) members
 		 * must not overlap with members from the other structs.
 		 * We accomplish this by putting its members at the very

include/sys/zfs_znode.h

@@ -212,7 +212,7 @@ typedef struct znode {
 
 	/*
 	 * Platform specific field, defined by each platform and only
-	 * accessable from platform specific code.
+	 * accessible from platform specific code.
 	 */
 	ZNODE_OS_FIELDS;
 } znode_t;

include/sys/zio_crypt.h

@@ -102,7 +102,7 @@ typedef struct zio_crypt_key {
 	crypto_key_t zk_current_key;
 
 #if defined(__FreeBSD__) && defined(_KERNEL)
-	/* Session for current encrpytion key.  Must always be set */
+	/* Session for current encryption key.  Must always be set */
 	freebsd_crypt_session_t	zk_session;
 #else
 	/* template of current encryption key for illumos crypto api */