modpost: remove mod->is_dot_o struct member

Previously, there were two cases where mod->is_dot_o is unset:

[1] the executable 'vmlinux' in the second pass of modpost
[2] modules loaded by read_dump()

I think [1] was intended usage to distinguish 'vmlinux.o' and 'vmlinux'.
Now that modpost does not parse the executable 'vmlinux', this case
does not happen.

[2] is obscure, maybe a bug. Module.symver stores module paths without
extension. So, none of modules loaded by read_dump() has the .o suffix,
and new_module() unsets ->is_dot_o. Anyway, it is not a big deal because
handle_symbol() is not called for the case.

To sum up, all the parsed ELF files are .o files.

mod->is_dot_o is unneeded.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

scripts/mod/modpost.h

@@ -126,7 +126,6 @@ struct module {
 	int has_cleanup;
 	struct buffer dev_table_buf;
 	char	     srcversion[25];
-	int is_dot_o;
 	// Missing namespace dependencies
 	struct namespace_list *missing_namespaces;
 	// Actual imported namespaces