objtool: Ignore unwind hints for ignored functions

If a function is ignored, also ignore its hints. This is useful for the
case where the function ignore is conditional on frame pointers, e.g.
STACK_FRAME_NON_STANDARD_FP().

Link: https://lkml.kernel.org/r/163163048317.489837.10988954983369863209.stgit@devnote2

Signed-off-by: Josh Poimboeuf <[e-mail]>
Reviewed-by: Masami Hiramatsu <[e-mail]>
Tested-by: Masami Hiramatsu <[e-mail]>
Signed-off-by: Steven Rostedt (VMware) <[e-mail]>

tools/objtool/check.c

···
 	}
 
 	while (&insn->list != &file->insn_list && (!sec || insn->sec == sec)) {
-		if (insn->hint && !insn->visited) {
+		if (insn->hint && !insn->visited && !insn->ignore) {
 			ret = validate_branch(file, insn->func, insn, state);
 			if (ret && backtrace)
 				BT_FUNC("<=== (hint)", insn);