iotop: backport some bugfix patches Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com> (cherry picked from commit c34f53122701d6820d851c1cfbfeb1d338e7073d) (cherry picked from commit 00d7df66ec022d90a4dc7408aac5bbfb870921ee)
(cherry picked from commit 07f54ea2f3b17a2188f1f84c22c13dbbf24e0306) (cherry picked from commit 43cd081c6cc28650c15ed5fed7f08082edc16f1e)
(cherry picked from commit 99fe8d54a0eb09ae21c59ef70348a23c1b791182) (cherry picked from commit a3ac071db144a067f1a737a2ce66728b4967422b)