objtool: Fix error handling for STD/CLD warnings

Actually return an error (and display a backtrace, if requested) for
directional bit warnings.

Fixes: 2f0f9e9a ("objtool: Add Direction Flag validation")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/dc70f2adbc72f09526f7cab5b6feb8bf7f6c5ad4.1611263461.git.jpoimboe@redhat.com

tools/objtool/check.c

@@ -2651,15 +2651,19 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 			break;
 
 		case INSN_STD:
-			if (state.df)
+			if (state.df) {
 				WARN_FUNC("recursive STD", sec, insn->offset);
+				return 1;
+			}
 
 			state.df = true;
 			break;
 
 		case INSN_CLD:
-			if (!state.df && func)
+			if (!state.df && func) {
 				WARN_FUNC("redundant CLD", sec, insn->offset);
+				return 1;
+			}
 
 			state.df = false;
 			break;