Revert part of 0dc2a65b82051f999c426f28e10e1ecf35ef5345.
Revert part of 0dc2a65b82051f999c426f28e10e1ecf35ef5345.

	* tests/libport/fd-stream.cc: Performing those side effect in
	BOOST_CHECK seems to provoke random failures, which is strange since
	the documentation specifies that expressions are evaluated once and
	only once. However, no time to investigate.

aldebaran/libport,aldebaran/libport,aldebaran/libport,aldebaran/libport,aldebaran/libport