od: move address_fmt[] from data to globals. 8 less bytes in data section

od: move address_fmt[] from data to globals. 8 less bytes in data section

function                                             old     new   delta
od_main                                             2164    2179     +15
address_fmt                                            8       -      -8
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 1/0 up/down: 15/-8)               Total: 7 bytes
   text    data     bss     dec     hex filename
 930954     481    6852  938287   e512f busybox_old
 930977     473    6852  938302   e513e busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>