t7407: Fix recursive submodule test

t7407: Fix recursive submodule test

A test in t7404-submodule-foreach purports to test that
the --cached flag is properly noticed by --recursive calls
to the foreach command as it descends into nested
submodules.  However, the test really does not perform this
test since the change it looks for is in a top-level
submodule handled by the first invocation of the command.
To properly test for the flag being passed to recursive
invocations, the change must be buried deeper in the
hierarchy.

Move the change one level deeper so it properly verifies
the recursive machinery of the 'git submodule status'
command.

Signed-off-by: Phil Hord <hordp@cisco.com>
Signed-off-by: Jeff King <peff@peff.net>