objtool: Avoid iterating !text section symbols

validate_functions() iterates all sections their symbols; this is
pointless to do for !text sections as they won't have instructions
anyway.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: NMiroslav Benes <mbenes@suse.cz>
Reviewed-by: NAlexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20200416115119.346582716@infradead.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

tools/objtool/check.c

@@ -2551,8 +2551,12 @@ static int validate_functions(struct objtool_file *file)
 	struct section *sec;
 	int warnings = 0;
 
-	for_each_sec(file, sec)
+	for_each_sec(file, sec) {
+		if (!(sec->sh.sh_flags & SHF_EXECINSTR))
+			continue;
+
 		warnings += validate_section(file, sec);
+	}
 
 	return warnings;
 }