Sump device capture init failure (blocking read & retry limit)

While testing the latest code snapshot with a Sump device, I discovered that the capture was failing.

At first due to a blocking read operation that was used to flush data during initialization.

Secondly the capture was initializing, but failing with a timeout before managing to trigger the hardware Sump device. To avoid this the retry limit was removed (since Stop button is expected to stop or cancel an acquisition attempt).

PS: A second commit was made to fix a small code formatting nonconformity that I introduced while implementing the above mentioned changes.