Fix typos in module/zfs/

Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Closes #9240

module/zfs/mmp.c

@@ -87,12 +87,12 @@
  *
  *    In this case, a weak guarantee is provided.  Since the host which last had
  *    the pool imported will suspend the pool if no mmp writes land within
- *    fail_intervals * multihost_interval ms, the absense of writes during that
+ *    fail_intervals * multihost_interval ms, the absence of writes during that
  *    time means either the pool is not imported, or it is imported but the pool
  *    is suspended and no further writes will occur.
  *
  *    Note that resuming the suspended pool on the remote host would invalidate
- *    this gurantee, and so it is not allowed.
+ *    this guarantee, and so it is not allowed.
  *
  *    The factor of 2 provides a conservative safety factor and derives from
  *    MMP_IMPORT_SAFETY_FACTOR;