Possible fix for stat error during globbing

Globs can fail when a directory is replaced with a file:
Error checking globs: stat foo: not a directory

Manually check for syscall.ENOTDIR, which is not covered by
fs.ErrNotExist.

Bug: 369548825
Test: manual
Flag: EXEMPT bugfix
Change-Id: I35f65725b70fc0abb22aff46298d053d98d03b00