Blackfin: export show_stack() to modules

Signed-off-by: Philippe Gerum <rpm@xenomai.org>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

arch/blackfin/kernel/traps.c

@@ -944,6 +944,7 @@ void show_stack(struct task_struct *task, unsigned long *stack)
 	}
 #endif
 }
+EXPORT_SYMBOL(show_stack);
 
 void dump_stack(void)
 {