fstrim.c: use open(O_DIRECTORY) instead of stat

open(O_DIRECTORY) returns an error if the open attempt
is against anything other than a directory. This basically
duplicates the check that the stat() call was trying to do.
Eliminate the unnecessary stat() call and use O_DIRECTORY
instead.

Change-Id: I1821abbed325f29a7214fdc41ed27cd9e26817d0
1 file changed