mm/memblock.c: trivial code refine in memblock_is_region_memory()

memblock_is_region_memory() invoke memblock_search() to see whether the
base address is in the memory region.  If it fails, idx would be -1.
Then, it returns 0.

If the memblock_search() returns a valid index, it means the base
address is guaranteed to be in the range memblock.memory.regions[idx].
Because of this, it is not necessary to check the base again.

This patch removes the check on "base".

Link: http://lkml.kernel.org/r/1482363033-24754-2-git-send-email-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memblock.c

@@ -1640,8 +1640,7 @@ int __init_memblock memblock_is_region_memory(phys_addr_t base, phys_addr_t size
 
 	if (idx == -1)
 		return 0;
-	return memblock.memory.regions[idx].base <= base &&
-		(memblock.memory.regions[idx].base +
+	return (memblock.memory.regions[idx].base +
 		 memblock.memory.regions[idx].size) >= end;
 }