Fix uninitialised VAX insn

Fix uninitialised VAX insn

MALLOC_PERTURB_=1 results in "FAIL: VAX ELF relocations", due to object
file being emitted with uninitialised fields.  Since these fields had
RELA relocs the field value won't be used at final link time, so the
problem is only seen in relocatable object files.

This rewrite of md_apply_fix clears all fields with relocs, whereas
before some fields had non-zero values.

gas/
	* config/tc-vax.c (md_apply_fix): Rewrite.
	(tc_gen_reloc, vax_cons, vax_cons_fix_new): Style: Use NO_RELOC
	define rather than the equivalent BFD_RELOC_NONE.
gas/testsuite/
	* gas/vax/elf-rel.d: Update.