unhuf.S is obsolete and no longer used

src/arch/i386/Makefile

 	$(BIN)/callbacks.o $(BIN)/pxe_callbacks.o
 
 SRCS+=	arch/i386/prefix/floppyprefix.S
-SRCS+=	arch/i386/prefix/unhuf.S
 SRCS+=	arch/i386/prefix/unnrv2b.S
 SRCS+=	arch/i386/firmware/pcbios/bios.c
 SRCS+=	arch/i386/firmware/pcbios/console.c