Fix a potential fd leak in fecomms.ml
Fix a potential fd leak in fecomms.ml

Signed-off-by: Jon Ludlam <e7e3380887a8f95cc9dc4f0d51dedc7e849a287a@eu.citrix.com>

djs55/forkexecd,johnelse/forkexecd,xapi-project/message-switch,xapi-project/message-switch,xapi-project/message-switch