linux-generic: validation: fix dependency for tests-validation.env
linux-generic: validation: fix dependency for tests-validation.env

The tests-validation.env file lists the test binaries/scripts to be run
during post-install testing, but the Makefile dependencies are wrong so
it gets created once and never updated. This means the following
sequence doesn't actually peform testing as expected -

./configure
make
./configure --enable-test-vald --with-testdir --prefix=$(pwd)/mytests
make install installcheck

As the tests-environment.env file generated during the first make (with
test-vald disabled) isn't updated.

Signed-off-by: Stuart Haslam <1fce01f364ef5298e64e07a42e08efeef153fa98@linaro.org>
Signed-off-by: Maxim Uvarov <db4d16e02ae2d7493db430203537da8b2e34f290@linaro.org>

ravineet-singh/odp,dkrot/odp,dkrot/odp,erachmi/odp,erachmi/odp,nmorey/odp,dkrot/odp,ravineet-singh/odp,erachmi/odp,nmorey/odp,rsalveti/odp,mike-holmes-linaro/odp,mike-holmes-linaro/odp,erachmi/odp,nmorey/odp,dkrot/odp,rsalveti/odp,ravineet-singh/odp,ravineet-singh/odp,nmorey/odp,mike-holmes-linaro/odp,mike-holmes-linaro/odp,rsalveti/odp,rsalveti/odp,rsalveti/odp