x86/dumpstack: Don't mention RIP in "Code: "

Commit

  238c911 ("x86/dumpstack: Fix misleading instruction pointer error message")

changed the "Code:" line in bug reports when RIP is an invalid pointer.
In particular, the report currently says (for example):

  BUG: kernel NULL pointer dereference, address: 0000000000000000
  ...
  RIP: 0010:0x0
  Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.

That

  Unable to access opcode bytes at RIP 0xffffffffffffffd6.

is quite confusing as RIP value is 0, not -42. That -42 comes from
"regs->ip - PROLOGUE_SIZE", because Code is dumped with some prologue
(and epilogue).

So do not mention "RIP" on this line in this context.

Signed-off-by: Jiri Slaby <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

arch/x86/kernel/dumpstack.c

@@ -128,7 +128,7 @@ void show_opcodes(struct pt_regs *regs, const char *loglvl)
 		/* No access to the user space stack of other tasks. Ignore. */
 		break;
 	default:
-		printk("%sCode: Unable to access opcode bytes at RIP 0x%lx.\n",
+		printk("%sCode: Unable to access opcode bytes at 0x%lx.\n",
 		       loglvl, prologue);
 		break;
 	}