mxser: rename CheckIsMoxaMust to mxser_get_must_hwid

CheckIsMoxaMust actually finds out what the card is. So rename it to
mxser_must_get_hwid, so that the name conforms to the semantics of the
function.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-7-jslaby@suse.cz


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