trivial: Add an explicit test for mtd-self-test to test-fwupd

mtd-self-test needs permissions to access mtdram, and mtdram must
be loaded.  Add an explicit test that runs elevated permissions and
loads that module.
diff --git a/contrib/test-venv.sh b/contrib/test-venv.sh
index 5e622b9..51cfcc7 100755
--- a/contrib/test-venv.sh
+++ b/contrib/test-venv.sh
@@ -3,6 +3,7 @@
 VENV=$(dirname $0)/..
 BUILD=${VENV}/build
 INSTALLED_TESTS=${VENV}/dist/share/installed-tests/fwupd
+SUDO=$(which sudo)
 export G_TEST_BUILDDIR=${INSTALLED_TESTS}
 export G_TEST_SRCDIR=${INSTALLED_TESTS}
 export GI_TYPELIB_PATH=${BUILD}/libfwupd
@@ -13,6 +14,12 @@
 echo "Build time test suite"
 ninja -C ${BUILD} test
 
+echo "Testing mtd-self-test"
+${SUDO} modprobe mtdram
+ENV="G_TEST_BUILDDIR=${G_TEST_BUILDDIR} \
+     G_TEST_SRCDIR=${G_TEST_SRCDIR}"
+${SUDO} ${ENV} ${VENV}/dist/libexec/installed-tests/fwupd/mtd-self-test
+
 echo "Testing fwupdtool.sh"
 ${INSTALLED_TESTS}/fwupdtool.sh