tty: Fix bogus "callbacks suppressed" messages

On the current git tree one sees messages such as:
 tty_init_dev: 24 callbacks suppressed
 tty_init_dev: 3 callbacks suppressed

To fix this we need to look at condition before calling __ratelimit in
the WARN_RATELIMIT macro. While at it remove the superfluous
__WARN_RATELIMIT macros.

Original patch is from Joe Perches and Jiri Slaby.

Signed-off-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Acked-and-tested-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>