vsock/test: fix vsock_ioctl_int() check for unsupported ioctl

`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: [e-mail]
Signed-off-by: Stefano Garzarella <[e-mail]>
Reviewed-by: Xuewei Niu <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

tools/testing/vsock/util.c

···
 	do {
 		ret = ioctl(fd, op, &actual);
 		if (ret < 0) {
-			if (errno == EOPNOTSUPP)
+			if (errno == EOPNOTSUPP || errno == ENOTTY)
 				break;
 
 			perror(name);