VMCI: Fix "always true condition"

vmci_send_datagram() returns an int, with negative values indicating failure.
But we store it locally in a u32, which makes comparison of >= 0 useless.
Fixed to use an int.

Reported-by: Dan Carpenter <[e-mail]>
Signed-off-by: Andy King <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/misc/vmw_vmci/vmci_guest.c

···
 u32 vmci_get_vm_context_id(void)
 {
 	if (vm_context_id == VMCI_INVALID_ID) {
-		u32 result;
+		int result;
 		struct vmci_datagram get_cid_msg;
 		get_cid_msg.dst =
 		    vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,