Revert "modpost: remove use of non-standard strsep() in HOSTCC code"

hulk inclusion
category: bugfix
bugzilla: 46847
CVE: NA

-----------------------------------------------

This reverts commit adcfc4574d9860c4a5d3f855438f0767bfaee7f7.

This series of patches could raise an issue on module built.

Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Reviewed-by: Jian Cheng <cj.chengjian@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>