Fix crash on getauxval call without HAVE_AUX_VECTOR

	* sysdeps/generic/ldsodefs.h (struct rtld_global_ro)
	[!HAVE_AUX_VECTOR]: Do not define _dl_auxv field.
	* misc/getauxval.c (__getauxval) [!HAVE_AUX_VECTOR]: Do not go through
	GLRO(dl_auxv) list.