Per commit 85a2d4a890dc ("x86,ibt: Use UDB instead of 0xEA"), make
sure objtool also recognises UDB as a #UD instruction.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 tools/objtool/arch/x86/decode.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -683,6 +683,10 @@ int arch_decode_instruction(struct objto
 		insn->type = INSN_SYSRET;
 		break;
 
+	case 0xd6: /* udb */
+		insn->type = INSN_BUG;
+		break;
+
 	case 0xe0: /* loopne */
 	case 0xe1: /* loope */
 	case 0xe2: /* loop */