hw/openrisc: Indent typo

Indent typo.

Signed-off-by: Jia Liu <proljc@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Andreas Färber <afaerber@suse.de>

hw/openrisc/openrisc_sim.c

@@ -96,7 +96,7 @@ static void openrisc_sim_init(QEMUMachineInitArgs *args)
     ram_addr_t ram_size = args->ram_size;
     const char *cpu_model = args->cpu_model;
     const char *kernel_filename = args->kernel_filename;
-   OpenRISCCPU *cpu = NULL;
+    OpenRISCCPU *cpu = NULL;
     MemoryRegion *ram;
     int n;