x86/dumpstack: Make printk_stack_address() more generally useful

Change printk_stack_address() to be useful when called by an unwinder
outside the context of dump_trace().

Specifically:

- printk_stack_address()'s 'data' argument is always used as the log
  level string.  Make that explicit.

- Call touch_nmi_watchdog().

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/9fbe0db05bacf66d337c162edbf61450d0cff1e2.1472057064.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/dumpstack.c

@@ -26,10 +26,11 @@ int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
 static int die_counter;
 
 static void printk_stack_address(unsigned long address, int reliable,
-		void *data)
+				 char *log_lvl)
 {
+	touch_nmi_watchdog();
 	printk("%s [<%p>] %s%pB\n",
-		(char *)data, (void *)address, reliable ? "" : "? ",
+		log_lvl, (void *)address, reliable ? "" : "? ",
 		(void *)address);
 }
 
@@ -148,7 +149,6 @@ static int print_trace_stack(void *data, char *name)
  */
 static int print_trace_address(void *data, unsigned long addr, int reliable)
 {
-	touch_nmi_watchdog();
 	printk_stack_address(addr, reliable, data);
 	return 0;
 }