tty: Documentation: fix a path in a DocBook template

A wrong path to a driver breaks DocBook built.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: NRandy Dunlap <rdunlap@infradead.org>
Acked-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/DocBook/device-drivers.tmpl

@@ -227,7 +227,7 @@ X!Isound/sound_firmware.c
   <chapter id="uart16x50">
      <title>16x50 UART Driver</title>
 !Edrivers/tty/serial/serial_core.c
-!Edrivers/tty/serial/8250/8250.c
+!Edrivers/tty/serial/8250/8250_core.c
   </chapter>
 
   <chapter id="fbdev">