all: Fix comment typos

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GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4481

cmd/stbench/main.go

@@ -92,7 +92,7 @@ loop:
 	return t1.Sub(t0)
 }
 
-// report stops the given process and reports on it's resource usage in two
+// report stops the given process and reports on its resource usage in two
 // ways: human readable to stderr, and CSV to stdout.
 func report(p *rc.Process, wallTime time.Duration) {
 	sv, err := p.SystemVersion()