linux-generic: test: shmem: close fifo
linux-generic: test: shmem: close fifo

Fixes: https://bugs.linaro.org/show_bug.cgi?id=2147 (CID 159394)
The fifo is closed at end of test

Signed-off-by: Christophe Milard <99616a981fa4477cda708a70f78076761c0c9f1c@linaro.org>
Reviewed-by: Mike Holmes <ed44c09f4d7f698f5510adc894a872c73e08c8bd@linaro.org>
Signed-off-by: Maxim Uvarov <db4d16e02ae2d7493db430203537da8b2e34f290@linaro.org>

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