USB: ftdi_sio whitespace fixes

Whitespace fixups for drivers/usb/serial/ftdi_sio.c ...
removing end-of-line whitespace, and space-before-tab.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>