swagger: fix naming

Use `DirtyMemory` of `MemoryDirty` for the object that includes the
bitmap with the dirty memory pages of guest memory. The former sounds
nicer.

Signed-off-by: Babis Chalios <babis.chalios@e2b.dev>

Author: bchalios

src/firecracker/swagger/firecracker.yaml

@@ -824,7 +824,7 @@ paths:
         200:
           description: OK
           schema:
-            $ref: "#/definitions/MemoryDirty"
+            $ref: "#/definitions/DirtyMemory"
         default:
           description: Internal server error
           schema:
@@ -1444,7 +1444,7 @@ definitions:
           type: integer
           format: uint64
 
-  MemoryDirty:
+  DirtyMemory:
     type: object
     description: Response containing the bitmap (one bit per page) of dirty pages of guest memory
     required: