fdisk: code shrink without logic changes

fdisk: code shrink without logic changes

function                                             old     new   delta
create_doslabel                                      113     110      -3
set_start_sect                                         8       4      -4
set_nr_sects                                           8       4      -4
get_start_sect                                         8       4      -4
get_nr_sects                                           8       4      -4
store4_little_endian                                  21       -     -21
read4_little_endian                                   33       -     -33
is_cleared_partition                                  84      21     -63
------------------------------------------------------------------------------
(add/remove: 0/2 grow/shrink: 0/6 up/down: 0/-136)           Total: -136 bytes

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