Correct spelling problems for Documentation/core-api/ as reported
by codespell.

Signed-off-by: Randy Dunlap <redacted>
Cc: Vladimir Oltean <olteanv@gmail.com>
Cc: netdev@vger.kernel.org
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: linux-crypto@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org

Reviewed-by: Mukesh Ojha <redacted>

-Mukesh