staging: wfx: fix a handful of spelling mistakes

There are various spelling mistakes in comments and error messages.
Fix these.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200806104701.46123-1-colin.king@canonical.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>