module: remove each_symbol_in_section

each_symbol_in_section just contains a trivial loop over its arguments.
Just open code the loop in the two callers.

Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>