mm/memblock.c: small function definition fixes

warning: function 'memblock_memory_can_coalesce'
with external linkage has definition.

Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memblock.c

@@ -267,7 +267,7 @@ static int __init_memblock memblock_double_array(struct memblock_type *type)
 	return 0;
 }
 
-extern int __init_memblock __weak memblock_memory_can_coalesce(phys_addr_t addr1, phys_addr_t size1,
+int __init_memblock __weak memblock_memory_can_coalesce(phys_addr_t addr1, phys_addr_t size1,
 					  phys_addr_t addr2, phys_addr_t size2)
 {
 	return 1;