Update some method Javadocs as they no longer return null

Author: doblon8

src/main/java/io/github/doblon8/openpnp/capture/CaptureDevice.java

@@ -28,8 +28,6 @@ public CaptureDevice(CaptureContext context, int deviceId) {
 
     /**
      * Get the name of a capture device.
-     * <p>
-     * If a device with the given id does not exist, null is returned.
      *
      * @param deviceId the device id of the capture device.
      * @return the name of the capture device.
@@ -48,8 +46,6 @@ private String getDeviceName(int deviceId) {
      * <p>
      * The string contains a unique concatenation of the device name and other parameters.
      * These parameters are platform dependent.
-     * <p>
-     * If a device with the given id does not exist, null is returned.
      *
      * @param deviceId the device id of the capture device.
      * @return the unique name of the capture device.