contrib: rpc_examples: haskell: fix ftbs with current libraries
And get rid of some warnings along the way.
Change-Id: I8fdbe1fa304276be6b0f25249b902b3576aa3793
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Reviewed-on: http://openocd.zylin.com/5987
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>