[PATCH] Temporary patch for arpd

Hello. I found wonderful bug in arpd daemon of iproute2 package.
Somehow arpd is absolute unworkable if run program with -f flag. On my
amd64 server i got "Segmentation fault" regardless -f mac-list.txt file
content.
The source of misc/arpd.c is not hard and i found that cause of
this bug is commit dd50247dba85255538d659551305b4bb75bcae62. I'm not
c++ developer, but i suppose segfault occured because argument of
dbase->put() has non-initialized dbdat.data argument.
Also arpd.c has strange condition "if (do_load || do_list)" that not
allows to run program with -f argument.
I did pull out the hexstring_a2n function from utils.c of previous commit
aeb199d5ce86c6c72decaac333cad5a7d7b38b3a and used it to populate
dbdat.data value after which program works fine.
I hurriedly make the patch that makes program alive. Please inspect
this problem, fix this bug and test program with -f key.
PS: sorry for my english =)