usb: typec: Fix num_altmodes kernel-doc error

The commit to introduce the num_altmodes attribute for partner had an
error where one of the parameters was named differently in the comment
and the function signature. Fix the version in the comment to align with
what is in the function signature.

This fixes the following htmldocs warning:

drivers/usb/typec/class.c:632: warning: Excess function parameter 'num_alt_modes' description in 'typec_partner_set_num_altmodes'

Fixes: a0ccdc4 ("usb: typec: Add number of altmodes partner attr")
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Prashant Malani <pmalani@chromium.org>
Link: https://lore.kernel.org/r/20201120063523.4159877-1-pmalani@chromium.org
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/typec/class.c

@@ -618,7 +618,7 @@ EXPORT_SYMBOL_GPL(typec_partner_set_identity);
 /**
  * typec_partner_set_num_altmodes - Set the number of available partner altmodes
  * @partner: The partner to be updated.
- * @num_alt_modes: The number of altmodes we want to specify as available.
+ * @num_altmodes: The number of altmodes we want to specify as available.
  *
  * This routine is used to report the number of alternate modes supported by the
  * partner. This value is *not* enforced in alternate mode registration routines.