iwlwifi: Fix comment typo

The double `only' is duplicated in the comment, remove one.

Signed-off-by: Jason Wang <wangborong@cdjrlc.com>
Link: https://patch.msgid.link/20220811120045.9422-1-wangborong@cdjrlc.com


Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>