Fix typo/boolean usage in stream eof comments (JuliaLang#46504)

Co-authored-by: Jameson Nash <[email protected]>

base/stream.jl

@@ -105,7 +105,7 @@ function eof(s::LibuvStream)
  bytesavailable(s) > 0 && return false
  wait_readnb(s, 1)
  # This function is race-y if used from multiple threads, but we guarantee
- # it to never return false until the stream is definitively exhausted
+ # it to never return true until the stream is definitively exhausted
  # and that we won't return true if there's a readerror pending (it'll instead get thrown).
  # This requires some careful ordering here (TODO: atomic loads)
  bytesavailable(s) > 0 && return false