MAINTAINERS: r8169: Update path to the driver

Update MAINTAINERS record to reflect the filename change.
The file was moved in commit 25e992a4 ("r8169: rename
r8169.c to r8169_main.c")

Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: nic_swsd@realtek.com
Cc: David S. Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Signed-off-by: Denis Efremov <efremov@linux.com>
Reviewed-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

MAINTAINERS

@@ -183,7 +183,7 @@ M:	Realtek linux nic maintainers <nic_swsd@realtek.com>
 M:	Heiner Kallweit <hkallweit1@gmail.com>
 L:	netdev@vger.kernel.org
 S:	Maintained
-F:	drivers/net/ethernet/realtek/r8169.c
+F:	drivers/net/ethernet/realtek/r8169*
 
 8250/16?50 (AND CLONE UARTS) SERIAL DRIVER
 M:	Greg Kroah-Hartman <gregkh@linuxfoundation.org>