lto: Don't check obj.found for offload section

obj.found is the number of LTO symbols.  We should include the offload
section when it is used by linker even if there are no LTO symbols.

	PR lto/116361
	* lto-plugin.c (claim_file_handler_v2): Don't check obj.found
	for the offload section.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>