Revert "Kbuild, lto, workaround: Don't warn for initcall_reference in modpost"

This reverts commit 77ab21ad.

Even after 8 years later, GCC LTO has not been upstreamed. Also, it said
"This is a workaround". If this is needed in the future, it should be
added in a proper way.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Jiri Slaby <jirislaby@kernel.org>

scripts/mod/modpost.c

@@ -1462,9 +1462,6 @@ static void default_mismatch_handler(const char *modname, struct elf_info *elf,
 	from = find_elf_symbol2(elf, r->r_offset, fromsec);
 	fromsym = sym_name(elf, from);
 
-	if (strstarts(fromsym, "reference___initcall"))
-		return;
-
 	tosec = sec_name(elf, get_secindex(elf, sym));
 	to = find_elf_symbol(elf, r->r_addend, sym);
 	tosym = sym_name(elf, to);