Fix unitialized variable in test path

Signed-off-by: Frédéric Dalleau <frederic.dalleau@collabora.com>

update-test-path

-PATH=${TESTPATH}/common:${TESTPATH}/bin:$PATH
+# Current test directory extracted from pwd
 TESTPATH=$(pwd)
+
+# Path for architecture independant binaries
+PATH=${TESTPATH}/common:${TESTPATH}/bin:$PATH
+
+# Path for architecture specific binaries
 case `uname -m` in
 x86_64) PATH=${TESTPATH}/amd64/bin:$PATH; ;;
 armv7l) PATH=${TESTPATH}/armhf/bin:$PATH; ;;