[ld, hurd] Remove 'ld-elf/elf.exp' XFAILs

[ld, hurd] Remove 'ld-elf/elf.exp' XFAILs

... as a follow-up to commit d98164028637041c5de99af0d057bde3f168a8a8 "Run more
ld tests when not native", which replaced by a proper solution the following
mess before present in 'ld/configure.host':

    -*-*-gnu*)
    -  # When creating static executables, we ought to use crt0.o instead of crt1.o,
    -  # <http://www.gnu.org/software/hurd/open_issues/binutils.html#static>,
    -  # but the testing infrastructure is not prepared for that.  This is not
    -  # relevant for most tests, and the few remaining ones have been XFAILed.
    -  HOSTING_CRT0='[...]'
    -  HOSTING_LIBS='[...]'

	ld/
	* testsuite/ld-elf/elf.exp: Remove Hurd XFAILs.