ram-block-attributes: Unify the retrieval of the block size

There's an existing helper function designed to obtain the block size.
Modify ram_block_attribute_create() to use this function for
consistency.

Tested-by: Farrah Chen <farrah.chen@intel.com>
Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
Link: https://lore.kernel.org/r/20251023095526.48365-3-chenyi.qiang@intel.com
[peterx: fix double spaces, per david]
Signed-off-by: Peter Xu <peterx@redhat.com>

system/ram-block-attributes.c

@@ -390,7 +390,7 @@ int ram_block_attributes_state_change(RamBlockAttributes *attr,
 
 RamBlockAttributes *ram_block_attributes_create(RAMBlock *ram_block)
 {
-    const int block_size  = qemu_real_host_page_size();
+    const int block_size = ram_block_attributes_get_block_size();
     RamBlockAttributes *attr;
     MemoryRegion *mr = ram_block->mr;