nds32/setup: remove unused memblock_region variable in setup_memory()

kernel test robot reports unused variable warning:

   arch/nds32/kernel/setup.c:247:26: warning: Unused variable: region
   [unusedVariable]
    struct memblock_region *region;
                            ^

Remove the unused variable.

Link: https://lkml.kernel.org/r/20210712125218.28951-1-rppt@kernel.orgSigned-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/nds32/kernel/setup.c

@@ -244,7 +244,6 @@ static void __init setup_memory(void)
 	unsigned long ram_start_pfn;
 	unsigned long free_ram_start_pfn;
 	phys_addr_t memory_start, memory_end;
-	struct memblock_region *region;
 
 	memory_end = memory_start = 0;