Fix remaining wsl_v5 whitespace findings (refs #61)

Insert the blank line wsl_v5 requires above `defer` and `go`
statements that share no variables with the statement above them.
Applied mechanically via `make lint-fix`; the diff is 60 added blank
lines and nothing else.

internal/snapshot/progress.go

@@ -127,6 +127,7 @@ func NewProgressReporter() *ProgressReporter {
 // Start begins the progress reporting
 func (pr *ProgressReporter) Start() {
 	pr.wg.Add(1)
+
 	go pr.run()
 
 	// Print initial multi-line status