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 

tests/zfs-tests/tests/functional/largest_pool/largest_pool_001_pos.ksh

@@ -158,4 +158,4 @@ for volsize in $VOLSIZES; do
 	destroy_pool $TESTPOOL2
 done
 
-log_pass "Dateset can be created, mounted & destroy in largest pool succeeded."
+log_pass "Dataset can be created, mounted & destroy in largest pool succeeded."

tests/zfs-tests/tests/functional/mmap/mmap_read_001_pos.ksh

@@ -40,7 +40,7 @@
 # 1. Create a pool & dataset
 # 2. Call readmmap binary
 # 3. unmount this file system
-# 4. Verify the integrity of this pool & dateset
+# 4. Verify the integrity of this pool & dataset
 #
 
 verify_runnable "global"

tests/zfs-tests/tests/functional/persist_l2arc/persist_l2arc_002_pos.ksh

@@ -29,13 +29,13 @@
 # STRATEGY:
 #	1. Create pool with a cache device.
 #	2. Create a an encrypted ZFS file system.
-#	3. Create a random file in the encyrpted file system and random
+#	3. Create a random file in the encrypted file system and random
 #		read for 30 sec.
 #	4. Export pool.
 #	5. Read the amount of log blocks written from the header of the
 #		L2ARC device.
 #	5. Import pool.
-#	6. Mount the encypted ZFS file system.
+#	6. Mount the encrypted ZFS file system.
 #	7. Read the amount of log blocks rebuilt in arcstats and compare to
 #		(5).
 #	8. Check if the labels of the L2ARC device are intact.

tests/zfs-tests/tests/functional/persist_l2arc/persist_l2arc_005_pos.ksh

@@ -34,7 +34,7 @@
 #	4. Export pool.
 #	5. Read amount of log blocks written.
 #	6. Import pool.
-#	7. Mount the encypted ZFS file system.
+#	7. Mount the encrypted ZFS file system.
 #	8. Read amount of log blocks built.
 #	9. Compare the two amounts
 #	10. Read the file written in (3) and check if l2_hits in

tests/zfs-tests/tests/functional/resilver/resilver_restart_001.ksh

@@ -26,7 +26,7 @@
 # DESCRIPTION:
 # Testing resilver restart logic both with and without the deferred resilver
 # feature enabled, verifying that resilver is not restarted when it is
-# unecessary.
+# unnecessary.
 #
 # STRATEGY:
 # 1. Create a pool

tests/zfs-tests/tests/functional/write_dirs/write_dirs_001_pos.ksh

@@ -37,7 +37,7 @@
 # is full. The zfs file system should be stable and works well.
 #
 # STRATEGY:
-# 1. Create a pool & dateset
+# 1. Create a pool & dataset
 # 2. Make directories in the zfs file system
 # 3. Create 50 big files in each directories
 # 4. Test case exit when the disk is full.

tests/zfs-tests/tests/functional/write_dirs/write_dirs_002_pos.ksh

@@ -37,7 +37,7 @@
 # is full. The zfs file system should be work well and stable.
 #
 # STRATEGY:
-# 1. Create a pool & dateset
+# 1. Create a pool & dataset
 # 2. Make directories in the zfs file system
 # 3. Create 5000 files in each directories
 # 4. Test case exit when the disk is full

tests/zfs-tests/tests/perf/regression/sequential_reads_dbuf_cached.ksh

@@ -25,7 +25,7 @@
 # for all fio runs. The ARC is not cleared to ensure that all data is cached.
 #
 # This is basically a copy of the sequential_reads_cached test case, but with
-# a smaller dateset so that we can fit everything into the decompressed, linear
+# a smaller dataset so that we can fit everything into the decompressed, linear
 # space in the dbuf cache.
 #