check: Check for pipe return value in check_unaligned_vmsplice

| cr-check.c: In function ‘check_unaligned_vmsplice’:
| cr-check.c:372:2: error: ignoring return value of ‘pipe’, declared with attribute warn_unused_result [-Werror=unused-result]
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

cr-check.c

@@ -369,7 +369,11 @@ static int check_unaligned_vmsplice(void)
 	char buf; /* :) */
 	struct iovec iov;
 
-	pipe(p);
+	ret = pipe(p);
+	if (ret < 0) {
+		pr_perror("Can't create pipe");
+		return -1;
+	}
 	iov.iov_base = &buf;
 	iov.iov_len = sizeof(buf);
 	ret = vmsplice(p[1], &iov, 1, SPLICE_F_GIFT | SPLICE_F_NONBLOCK);