Fix host-run-test-jar to be legal for /bin/sh

At least on my machine, /bin/sh complains about the [[ line.
Rewrite as a standard shell 'if'

Change-Id: I68efc4ceab8e2eb5636fa04ce8877883a4d76998
Signed-off-by: Mark Mendell <mark.p.mendell@intel.com>
diff --git a/test/etc/host-run-test-jar b/test/etc/host-run-test-jar
index da74532..997e84b 100755
--- a/test/etc/host-run-test-jar
+++ b/test/etc/host-run-test-jar
@@ -79,7 +79,9 @@
 msg "------------------------------"
 
 mkdir $DEX_LOCATION/dalvik-cache
-[[ $? -ne 0 ]] && exit
+if [ $? -ne 0 ]; then
+    exit
+fi
 
 export ANDROID_PRINTF_LOG=brief
 if [ "$DEV_MODE" = "y" ]; then