QArrayDataPointer: use Data::deallocate() instead of raw free()

Be symmetrical with the Data::allocate() in the constructor.

This is not strictly a no-op since we now call the exported symbol
QArrayData::deallocate() instead of inlining a free() call. However, it
allows future sized-free optimizations.

Pick-to: 6.8
Change-Id: I2ef00a897f56a32a0f1188f69f159834e6ca5b64
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
(cherry picked from commit 41c47fdd192cafa001b6e67defc314af5c1d6316)

src/corelib/tools/qarraydatapointer.h

@@ -107,7 +107,7 @@ public:
     {
         if (!deref()) {
             (*this)->destroyAll();
-            free(d);
+            Data::deallocate(d);
         }
     }