Input: synaptics-rmi4 - fix function name in kerneldoc

No functional modification involved.

drivers/input/rmi4/rmi_bus.c:300: warning: expecting prototype for rmi_register_function_handler(). Prototype was for __rmi_register_function_handler() instead.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Link: https://lore.kernel.org/r/20230209040710.111456-1-jiapeng.chong@linux.alibaba.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/rmi4/rmi_bus.c

@@ -285,7 +285,7 @@ void rmi_unregister_function(struct rmi_function *fn)
 }
 
 /**
- * rmi_register_function_handler - register a handler for an RMI function
+ * __rmi_register_function_handler - register a handler for an RMI function
  * @handler: RMI handler that should be registered.
  * @owner: pointer to module that implements the handler
  * @mod_name: name of the module implementing the handler