Tighten spl dependency on spl-kmod

Make spl depend on the same version of spl-kmod, rather than on same or
better. When yum repository contains a number of versions the dependency
resolution breaks on trying to install non-latest version.

Signed-off-by: Cyril Plisko <cyril.plisko@mountall.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes zfsonlinux/zfs#1677
Retroactively fix bogus %changelog date

New versions of rpmbuild detect the invalid date which was added
incorrectly to the changelog.  To silence this noise fix it.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #306