usb: host: fhci-tds: Remove unused variables 'buf' and 'extra_data'

usb: host: fhci-tds: Remove unused variables 'buf' and 'extra_data'

Neither have been used since the driver's inception in 2009.

Fixes the following W=1 kernel build warning(s):

 drivers/usb/host/fhci-tds.c: In function ‘fhci_flush_bds’:
 drivers/usb/host/fhci-tds.c:472:6: warning: variable ‘buf’ set but not used [-Wunused-but-set-variable]
 472 | u32 buf;
 | ^~~
 drivers/usb/host/fhci-tds.c:470:6: warning: variable ‘extra_data’ set but not used [-Wunused-but-set-variable]
 470 | u16 extra_data;
 | ^~~~~~~~~~
 drivers/usb/host/fhci-tds.c: In function ‘fhci_flush_actual_frame’:
 drivers/usb/host/fhci-tds.c:527:6: warning: variable ‘extra_data’ set but not used [-Wunused-but-set-variable]
 527 | u16 extra_data;
 | ^~~~~~~~~~

Cc: Shlomi Gridish <gridish@freescale.com>
Cc: Jerry Huang <Chang-Ming.Huang@freescale.com>
Cc: Peter Barada <peterb@logicpd.com>
Cc: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200706133341.476881-31-lee.jones@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>