rhel: Make openvswitch-kmod-fedora.spec build.

rhel: Make openvswitch-kmod-fedora.spec build.

I tried building this package on Fedora 23 and it failed for a couple of
different reasons.

This package tried to install modules without specifying the rpm build
root as an install prefix.  The result was just attempting to install
the modules on the system, which luckily failed since I wasn't running
rpmbuild as root.

The package also then tried to manually install the modules into the rpm
build root, which is unnecessary once modules_install is pointed to the
right place.

Finally, the package build failed with a completely unhelpful error
which turned out to be because it didn't know how to generate
a debuginfo pacakge.  I turned off the debug package for now.  At least
it builds now, which is an improvement.

Signed-off-by: Russell Bryant <russell@ovn.org>
Suggested-by: Flavio Leitner <fbl@redhat.com>
Acked-by: Flavio Leitner <fbl@redhat.com>
Acked-by: Gurucharan Shetty <guru@ovn.org>