vma01: check kernel version

This is just a kernel behaviour change to avoid the possible
scalability issue, not a real kernel bug. So, check the kernel
version.

Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Acked-by: Cyril Hrubis <chrubis@suse.cz>

testcases/kernel/mem/vma/vma01.c

@@ -192,7 +192,13 @@ static void check_status(int status)
 		tst_resm(TPASS, "two 3*ps VMAs found.");
 		break;
 	case 1:
-		tst_resm(TFAIL, "A single 6*ps VMA found.");
+		if (tst_kvercmp(3, 0, 0) < 0) {
+			tst_resm(TCONF, "A single 6*ps VMA found. You may need"
+					" to back port kernel commit 965f55d "
+					"to fix this scalability issue.");
+		} else {
+			tst_resm(TFAIL, "A single 6*ps VMA found.");
+		}
 		break;
 	default:
 		tst_brkm(TBROK, cleanup, "unexpected VMA found.");