Tidy objdump_symstuff and objdump_dynsymstuff

	* testsuite/ld-elfvers/vers.exp (objdump_symstuff): Remove unused
	variable.  Init list_a and list_b to empty.
	(objdump_dynsymstuff): Likewise, and remove undefined list_a
	handling.
	* testsuite/ld-elfweak/elfweak.exp (objdump_symstuff): Similarly.
	(objdump_dynsymstuff): Similarly.