libxdp: fix prog_fd checks for fd >= 0

Make sure all checks for whether prog_fd is set checks for >= 0 instead of
just checking the fd as a boolean.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>

lib/libxdp/libxdp.c

@@ -525,7 +525,7 @@ xdp_program__is_attached(const struct xdp_program *xdp_prog, int ifindex)
 int xdp_program__set_chain_call_enabled(struct xdp_program *prog,
 					unsigned int action, bool enabled)
 {
-	if (!prog || prog->prog_fd || action >= XDP_DISPATCHER_RETVAL)
+	if (!prog || prog->prog_fd >= 0 || action >= XDP_DISPATCHER_RETVAL)
 		return -EINVAL;
 
 	if (enabled)
@@ -555,7 +555,7 @@ unsigned int xdp_program__run_prio(const struct xdp_program *prog)
 
 int xdp_program__set_run_prio(struct xdp_program *prog, unsigned int run_prio)
 {
-	if (!prog || prog->prog_fd)
+	if (!prog || prog->prog_fd >= 0)
 		return -EINVAL;
 
 	prog->run_prio = run_prio;