objtool/klp: Simplify reloc symbol conversion

objtool/klp: Simplify reloc symbol conversion

Inline section_reference_needed() and is_reloc_allowed() into
convert_reloc_sym() and remove the redundant is_reloc_allowed() check in
clone_reloc().

Move the is_sec_sym() checks into the convert callees so they become
no-ops when the reloc is already in the right format.  This allows
convert_reloc_sym() to unconditionally dispatch to the right converter
based on section type.

Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>