drivers/tty: Remove unneeded spaces

coding style fixes in n_tty.c
Signed-off-by: NMaximilian Krger <maxfragg@gmail.com>
Signed-off-by: NThorsten Wimann <re06huxa@cip.cs.fau.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>