[NFC][test] Fix the line num of expected-error for CSKY at builtin-alloca-with-align.c

clang/test/Sema/builtin-alloca-with-align.c

@@ -31,7 +31,7 @@ void test7(int a) {
 void test8(void) {
   __builtin_alloca_with_align(sizeof(__INT64_TYPE__), __alignof__(__INT64_TYPE__)); // expected-warning {{second argument to __builtin_alloca_with_align is supposed to be in bits}}
 #if defined(__csky__)
-  // expected-error@-1 {{requested alignment must be 8 or greater}}
+  // expected-error@-2 {{requested alignment must be 8 or greater}}
   // Because the alignment of long long is 4 in CSKY target
 #endif
 }