hdparm: flag variables can easily be smaller than long

hdparm: flag variables can easily be smaller than long

function                                             old     new   delta
process_dev                                         5247    5325     +78
bb_ioctl_on_off                                       72      78      +6
unregister_hwif                                        4       1      -3
...
perform_reset                                          4       1      -3
parse_xfermode                                       111     108      -3
noisy_piomode                                          4       1      -3
...
do_flush                                               4       1      -3
do_ctimings                                            4       1      -3
static.parm                                            4       -      -4
static.multcount                                       4       -      -4
parse_opts                                            54      48      -6
hdparm_main                                         1435    1383     -52
------------------------------------------------------------------------------
(add/remove: 0/2 grow/shrink: 2/61 up/down: 84/-243)         Total: -159 bytes