run-test-jar: replace tempfile with mktemp

Test: art/test.py --64 --host
Test: Treehugger
Change-Id: I1bf655078bc2dc2194fb71b9de62de5dbf2707d7
diff --git a/test/etc/run-test-jar b/test/etc/run-test-jar
index 3c179dc..adef285 100755
--- a/test/etc/run-test-jar
+++ b/test/etc/run-test-jar
@@ -1248,11 +1248,8 @@
              $sync_cmdline && \
              $timeout_prefix $dalvikvm_cmdline"
 
-    # Redirect tempfile error output to /dev/null to silence
-    #     WARNING: tempfile is deprecated; consider using mktemp instead.
-    # seen on device.
-    cmdfile=$(tempfile -p "cmd-" -s "-$TEST_NAME" 2>/dev/null)
-    echo "$cmdline" > $cmdfile
+    cmdfile=$(mktemp cmd-XXXX --suffix "-$TEST_NAME")
+    echo "$cmdline" >> $cmdfile
 
     if [ "$DEV_MODE" = "y" ]; then
       echo $cmdline