The UEFI spec implies that GPT partitions should be assumed to be on a 2048
sector boundary (for a 512 byte sector) and the current logic just
divides the free sectors available by the number of partitions that need
re-sizing, which may or may not align and the final result might
overshoot the limits imposed after alignment.
Since we are expanding already aligned partitions, just divide up the
free space in multiples of 2048. Also use the exec_cmd wrapper instead
of the subprocess call directly.
Fixes [YOCTO #12840]
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
