bzip2: move state pointer to the offset 0 (smaller code)

bzip2: move state pointer to the offset 0 (smaller code)
ifdef out DecompressEnd if FEATURE_CLEAN_UP is not seleted

fallbackSort                                        1655    1672     +17
mainSort                                            2447    2458     +11
bzip2_main                                           109     119     +10
.rodata                                           123466  123469      +3
generateMTFValues                                    433     435      +2
handle_compress                                      355     356      +1
BZ2_bzCompress                                        79      78      -1
prepare_new_block                                     55      48      -7
compressStream                                       547     503     -44
sendMTFValues                                       2225    2140     -85
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 6/4 up/down: 44/-137)           Total: -93 bytes
   text    data     bss     dec     hex filename
 676421    2538   12104  691063   a8b77 busybox_old
 676328    2538   12104  690970   a8b1a busybox_unstripped