Do not fail 'devctl clear driver' if another driver is not found

Detaching the bhyve(4) ppt driver from an unsupported PCI device
should not raise a "Device not configured" error.  We do not expect
that a new driver must take over the device in this case.

Reviewed by:	imp, jhb
Differential Revision:	https://reviews.freebsd.org/D52050

lib/libdevctl/devctl.3

@@ -22,7 +22,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd April 4, 2019
+.Dd February 24, 2026
 .Dt DEVCTL 3
 .Os
 .Sh NAME
@@ -193,6 +193,7 @@ is true,
 the device will be detached from its current device driver.
 After the device's name is reset,
 it is reprobed and attached to a suitable device driver if one is found.
+If no suitable device driver is found, no error is reported.
 .Pp
 The
 .Fn devctl_rescan

sys/kern/subr_bus.c

@@ -5961,7 +5961,19 @@ devctl2_ioctl(struct cdev *cdev, u_long cmd, caddr_t data, int fflag,
 		dev->flags &= ~DF_FIXEDCLASS;
 		dev->flags |= DF_WILDCARD;
 		devclass_delete_device(dev->devclass, dev);
-		error = device_probe_and_attach(dev);
+
+		/*
+		 * Don't use device_probe_and_attach so that failing
+		 * to find a new driver isn't reported as an error.
+		 */
+		error = device_probe(dev);
+		if (error == ENXIO) {
+			error = 0;
+			break;
+		}
+		if (error == 0) {
+			error = device_attach(dev);
+		}
 		break;
 	case DEV_RESCAN:
 		if (!device_is_attached(dev)) {