x86: remove unnecessary save_mr() sanity check

Impact: cleanup

The save_mr() function already checks that start_pfn is less than
end_pfn so we can remove the unnecessary check which reduces the
diff between the 32-bit and the 64-bit versions of init_memory_mapping().
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <1236257708-27269-6-git-send-email-penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/mm/init_32.c

@@ -1008,7 +1008,6 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
 	/* tail is not big page (2M) alignment */
 	start_pfn = pos>>PAGE_SHIFT;
 	end_pfn = end>>PAGE_SHIFT;
-	if (start_pfn < end_pfn)
 	nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
 
 	/* try to merge same page size and continuous */