It must get boring translating all the variants we have of
unrecognized/unsupported/invalid/unexpected reloc number.  This patch
cuts down on the number of variations.

	* aoutx.h, * coff-alpha.c, * coff-i860.c, * coff-m68k.c,
	* coff-mcore.c, * coff-ppc.c, * coff-rs6000.c, * coff-sh.c,
	* coff-tic4x.c, * coff-tic54x.c, * coff-tic80.c, * coff-w65.c,
	* elf-bfd.h, * elf-m10300.c, * elf.c, * elf32-avr.c, * elf32-bfin.c,
	* elf32-cr16.c, * elf32-cr16c.c, * elf32-cris.c, * elf32-crx.c,
	* elf32-d10v.c, * elf32-d30v.c, * elf32-dlx.c, * elf32-epiphany.c,
	* elf32-fr30.c, * elf32-frv.c, * elf32-i370.c, * elf32-i386.c,
	* elf32-i960.c, * elf32-ip2k.c, * elf32-iq2000.c, * elf32-lm32.c,
	* elf32-m32c.c, * elf32-m32r.c, * elf32-m68hc11.c, * elf32-m68hc12.c,
	* elf32-m68k.c, * elf32-mcore.c, * elf32-mep.c, * elf32-metag.c,
	* elf32-microblaze.c, * elf32-mips.c, * elf32-moxie.c,
	* elf32-msp430.c, * elf32-mt.c, * elf32-nds32.c, * elf32-or1k.c,
	* elf32-pj.c, * elf32-ppc.c, * elf32-rl78.c, * elf32-rx.c,
	* elf32-s390.c, * elf32-sh.c, * elf32-spu.c, * elf32-tic6x.c,
	* elf32-v850.c, * elf32-vax.c, * elf32-visium.c, * elf32-wasm32.c,
	* elf32-xgate.c, * elf32-xtensa.c, * elf64-alpha.c,
	* elf64-ia64-vms.c, * elf64-mips.c, * elf64-mmix.c,
	* elf64-ppc.c, * elf64-s390.c, * elf64-sparc.c, * elf64-x86-64.c,
	* elfn32-mips.c, * elfnn-aarch64.c, * elfnn-ia64.c,
	* elfnn-riscv.c, * elfxx-mips.c, * elfxx-riscv.c, * elfxx-riscv.h,
	* elfxx-sparc.c, * elfxx-sparc.h, * reloc.c: Standardize
	unrecognized/unsupported reloc message.