hw/arm/mps2-tz.c: Free mscname string in make_dma()

The clang leak sanitizer spots a (one-off, trivial) memory
leak in make_dma() due to a missing free.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20181204132952.2601-3-peter.maydell@linaro.org

hw/arm/mps2-tz.c

@@ -322,6 +322,7 @@ static MemoryRegion *make_dma(MPS2TZMachineState *mms, void *opaque,
     sysbus_connect_irq(s, 2, qdev_get_gpio_in_named(iotkitdev,
                                                     "EXP_IRQ", 57 + i * 3));
 
+    g_free(mscname);
     return sysbus_mmio_get_region(s, 0);
 }