sh: remove warning and warning_symbol from struct stacktrace_ops

Both warning and warning_symbol are nowhere used.
Let's get rid of them.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/include/asm/stacktrace.h

@@ -10,9 +10,6 @@
 /* Generic stack tracer with callbacks */
 
 struct stacktrace_ops {
-	void (*warning)(void *data, char *msg);
-	/* msg must contain %s for the symbol */
-	void (*warning_symbol)(void *data, char *msg, unsigned long symbol);
 	void (*address)(void *data, unsigned long address, int reliable);
 	/* On negative return stop dumping */
 	int (*stack)(void *data, char *name);