[PATCH] More !tty cleanups in drivers/char

Another bunch of checks in the char drivers .put_char() and .write()
routines, where tty can never be NULL.  This patch removes these checks to
save some code.  Coverity choked at those with the following bug ids:

isicom.c  767, 766
specialix.c 773, 774
synclink_cs.c 779, 781
synclink_gt.c 784, 785
synclinkmp.c 784, 785

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>