hw/arm/xlnx-zynqmp.c: Avoid memory leak in error-return path

In xlnx_zynqmp_realize() if the attempt to realize the SD
controller object fails then the error-return path will leak
the 'bus_name' string. Fix this by deferring the allocation
until after the realize has succeeded.

Fixes: Coverity CID 1421911
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20200324134947.15384-2-peter.maydell@linaro.org

hw/arm/xlnx-zynqmp.c

@@ -520,7 +520,7 @@ static void xlnx_zynqmp_realize(DeviceState *dev, Error **errp)
     sysbus_connect_irq(SYS_BUS_DEVICE(&s->sata), 0, gic_spi[SATA_INTR]);
 
     for (i = 0; i < XLNX_ZYNQMP_NUM_SDHCI; i++) {
-        char *bus_name = g_strdup_printf("sd-bus%d", i);
+        char *bus_name;
         SysBusDevice *sbd = SYS_BUS_DEVICE(&s->sdhci[i]);
         Object *sdhci = OBJECT(&s->sdhci[i]);
 
@@ -541,6 +541,7 @@ static void xlnx_zynqmp_realize(DeviceState *dev, Error **errp)
         sysbus_connect_irq(sbd, 0, gic_spi[sdhci_intr[i]]);
 
         /* Alias controller SD bus to the SoC itself */
+        bus_name = g_strdup_printf("sd-bus%d", i);
         object_property_add_alias(OBJECT(s), bus_name, sdhci, "sd-bus",
                                   &error_abort);
         g_free(bus_name);