Add test.out to .gitignore and limit toplevel matches

The "keyctl" pattern was causing the tests/keyctl directory to be
ignored. Adding a leading "/" to names expected to be in the toplevel
directory ensures that they don't match names in subdirectories.

Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>