api.c: fix TOCTOU in cg_chmod_path()

api.c: fix TOCTOU in cg_chmod_path()

Fix TOCTOU warning, reported by Coverity Tool:

CID 258267 (#1 of 1): Time of check time of use (TOCTOU).
fs_check_call: Calling function stat to perform check on path.

in cg_chmod_path(), the file name is stat() and not immediately followed
by the file operation. One way to fix it, open the file and use the file
descriptor to manipulate the file.

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>