dump with r_addend is not correct

[ZYHowell]

I'm writing an assembler to generate relocatable object file and using dump function of rv8 to debug(btw, its output format is really nice). The file is little endian. But I've found that the dump of relocations has a bug: the r_addend is incorrect. As I forgot to memset Elf32_Rela, the r_addend member was incorrectly not zero, but in dumped result it is actually zero.