rapidio: fix kernel-doc a markup

Probaly this was due to a cut and paste issue.

Signed-off-by: Mauro Carvalho Chehab <[e-mail]>
Link: https://lore.kernel.org/r/e23e64[e-mail]
Signed-off-by: Jonathan Corbet <[e-mail]>

drivers/rapidio/rio.c

···
 EXPORT_SYMBOL_GPL(rio_map_outb_region);
 
 /**
- * rio_unmap_inb_region -- Unmap the inbound memory region
+ * rio_unmap_outb_region -- Unmap the inbound memory region
  * @mport: Master port
  * @destid: destination id mapping points to
  * @rstart: RIO base address window translates to