diff: stop using data/bss

diff: stop using data/bss

function                                             old     new   delta
do_diff                                              385     436     +51
diff_main                                            850     895     +45
dump_unified_vec                                     437     457     +20
prepare                                              335     334      -1
anychange                                              1       -      -1
suff                                                   4       -      -4
status                                               135     131      -4
static.max_context                                     4       -      -4
start                                                 12       8      -4
pref                                                   4       -      -4
member                                                 4       -      -4
label2                                                 4       -      -4
label1                                                 4       -      -4
klist                                                  4       -      -4
ixold                                                  4       -      -4
ixnew                                                  4       -      -4
dl_count                                               4       -      -4
dl                                                     4       -      -4
context_vec_start                                      4       -      -4
context_vec_ptr                                        4       -      -4
context_vec_end                                        4       -      -4
context                                                4       -      -4
clistlen                                               4       -      -4
clist                                                  4       -      -4
clen                                                   4       -      -4
class                                                  4       -      -4
J                                                      4       -      -4
add_to_dirlist                                        71      64      -7
slen                                                   8       -      -8
sfile                                                  8       -      -8
len                                                    8       -      -8
file                                                   8       -      -8
get_dir                                              196     185     -11
newcand                                               97      85     -12
change                                               351     331     -20
stb2                                                  96       -     -96
stb1                                                  96       -     -96
diffreg                                             2835    2717    -118
------------------------------------------------------------------------------
(add/remove: 0/27 grow/shrink: 3/8 up/down: 116/-482)        Total: -366 bytes

# size */*/diff.o
   text    data     bss     dec     hex filename
   7055       8     305    7368    1cc8 busybox.t2/coreutils/diff.o
   7002       0       0    7002    1b5a busybox.t3/coreutils/diff.o