Bug 6620 Ensure autoflush is set on output filehandles

Bug 6620 Ensure autoflush is set on output filehandles

stdout is by default buffered and a flush is only guaranteed on CR
Sip responses are not CR terminated so we need to ensure autoflush
is switched on  so that the filehandle is flushed after a print
Otherwise this can manifest as self checks running slow or
failing due to timeout (although in the log we see the response)

Signed-off-by: Ulrich Kleiber <ulrich.kleiber@bsz-bw.de>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
(cherry picked from commit f9ccfae400324fdd88597ff81fba42715e50f19d)

Signed-off-by: Chris Nighswonger <chris.nighswonger@gmail.com>