`vsock_do_ioctl` returns -ENOIOCTLCMD if an ioctl support is not
implemented, like for SIOCINQ before commit 
f7c722659275 ("vsock: Add
support for SIOCINQ ioctl"). In net/socket.c, -ENOIOCTLCMD is re-mapped
to -ENOTTY for the user space. So, our test suite, without that commit
applied, is failing in this way:
    34 - SOCK_STREAM ioctl(SIOCINQ) functionality...ioctl(21531): Inappropriate ioctl for device
Return false in vsock_ioctl_int() to skip the test in this case as well,
instead of failing.
Fixes: 53548d6bffac ("test/vsock: Add retry mechanism to ioctl wrapper")
Cc: niuxuewei.nxw@antgroup.com
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Xuewei Niu <niuxuewei.nxw@antgroup.com>
Link: https://patch.msgid.link/20250715093233.94108-1-sgarzare@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
        do {
                ret = ioctl(fd, op, &actual);
                if (ret < 0) {
-                       if (errno == EOPNOTSUPP)
+                       if (errno == EOPNOTSUPP || errno == ENOTTY)
                                break;
 
                        perror(name);