xtensa: fix stack dump output

Use %pB in pr_cont format string instead of calling print_symbol
separately. It turns

  [   19.166249] Call Trace:
  [   19.167265]  [<a000e50a>]
  [   19.167843]  __warn+0x92/0xa0
  [   19.169656]  [<a000e554>]
  [   19.170059]  warn_slowpath_fmt+0x3c/0x40
  [   19.171934]  [<a02d5bd8>]

back into

  [   18.123240] Call Trace:
  [   18.125039]  [<a000e4f6>] __warn+0x92/0xa0
  [   18.126961]  [<a000e540>] warn_slowpath_fmt+0x3c/0x40
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/kernel/traps.c

@@ -483,10 +483,8 @@ void show_regs(struct pt_regs * regs)
 
 static int show_trace_cb(struct stackframe *frame, void *data)
 {
-	if (kernel_text_address(frame->pc)) {
-		pr_cont(" [<%08lx>]", frame->pc);
-		print_symbol(" %s\n", frame->pc);
-	}
+	if (kernel_text_address(frame->pc))
+		pr_cont(" [<%08lx>] %pB\n", frame->pc, (void *)frame->pc);
 	return 0;
 }