mark device faulty after parent fails to suspend

When an error is returned here, unlike the other error returns in the function, nothing is done to mark the added device as faulty or remove it.
I have observed this causing future snapshot creations to continue to attempt to use the same ID (from the sequence) to create new devices
and get blocked because the device already exists because it was not rolled back here.

Hopefully fixes #5110

Signed-off-by: Jeremy Williams <ctrlaltdel121@gmail.com>

snapshots/devmapper/pool_device.go

@@ -331,12 +331,6 @@ func (p *PoolDevice) CreateSnapshotDevice(ctx context.Context, deviceName string
 		}
 	}()
 
-	// Save snapshot metadata and allocate new device ID
-	metaErr = p.metadata.AddDevice(ctx, snapInfo)
-	if metaErr != nil {
-		return metaErr
-	}
-
 	// The base device must be suspend before taking a snapshot to
 	// avoid corruption.
 	// https://github.com/torvalds/linux/blob/v5.7/Documentation/admin-guide/device-mapper/thin-provisioning.rst#internal-snapshots
@@ -354,6 +348,12 @@ func (p *PoolDevice) CreateSnapshotDevice(ctx context.Context, deviceName string
 		}()
 	}
 
+	// Save snapshot metadata and allocate new device ID
+	metaErr = p.metadata.AddDevice(ctx, snapInfo)
+	if metaErr != nil {
+		return metaErr
+	}
+
 	// Create thin device snapshot
 	devErr = p.createSnapshot(ctx, baseInfo, snapInfo)
 	if devErr != nil {