x86/mm/pat: cpa-test: fix length for CPA_ARRAY test

The CPA_ARRAY test always uses len[1] as numpages argument to
change_page_attr_set() although the addresses array is different each
iteration of the test loop.

Replace len[1] with len[i] to have numpages matching the addresses array.

Fixes: ecc729f ("x86/mm/cpa: Add ARRAY and PAGES_ARRAY selftests")
Signed-off-by: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250126074733.1384926-2-rppt@kernel.org

arch/x86/mm/pat/cpa-test.c

@@ -183,7 +183,7 @@ static int pageattr_test(void)
 			break;
 
 		case 1:
-			err = change_page_attr_set(addrs, len[1], PAGE_CPA_TEST, 1);
+			err = change_page_attr_set(addrs, len[i], PAGE_CPA_TEST, 1);
 			break;
 
 		case 2: