n_tty: check printk arguments for n_tty_trace

When N_TTY_TRACE is undefined (the default), define n_tty_trace to use
no_printk. That way, arguments are still checked during compilation.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200130115843.7452-1-jslaby@suse.czSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/n_tty.c

@@ -84,7 +84,7 @@
 #ifdef N_TTY_TRACE
 # define n_tty_trace(f, args...)	trace_printk(f, ##args)
 #else
-# define n_tty_trace(f, args...)
+# define n_tty_trace(f, args...)	no_printk(f, ##args)
 #endif
 
 struct n_tty_data {