cxl/region: uninitialized variable in alloc_hpa()

This should check "p->res" instead of "res" (which is uninitialized).

Fixes: 23a22cd1c9 ("cxl/region: Allocate HPA capacity to regions")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/Yueor88I/DkVSOtL@kili
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/cxl/core/region.c

@@ -454,7 +454,7 @@ static int alloc_hpa(struct cxl_region *cxlr, resource_size_t size)
 	lockdep_assert_held_write(&cxl_region_rwsem);
 
 	/* Nothing to do... */
-	if (p->res && resource_size(res) == size)
+	if (p->res && resource_size(p->res) == size)
 		return 0;
 
 	/* To change size the old size must be freed first */