mux: Fix struct mux_state kernel-doc comment

A warning is reported because a colon was dropped, it is found by running
scripts/kernel-doc, which is caused by using 'make W=1'.
drivers/mux/core.c:44: warning: Function parameter or member 'state' not
described in 'mux_state'
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Peter Rosin <peda@axentia.se>
Link: https://lore.kernel.org/r/a9a970fc-63f9-5ab9-4983-fba5b01bebe2@axentia.seSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/mux/core.c

@@ -33,7 +33,7 @@
  * struct mux_state -	Represents a mux controller state specific to a given
  *			consumer.
  * @mux:		Pointer to a mux controller.
- * @state		State of the mux to be selected.
+ * @state:		State of the mux to be selected.
  *
  * This structure is specific to the consumer that acquires it and has
  * information specific to that consumer.