haven: Fix memory leak

If haven returns an error in response to a message sent over hh_rm_msgq,
free connection->recv_buff prior to returning an error to the caller.

Change-Id: Ia23dcbb6a5bdb3d7a037d537e7dcf61695991a66
Signed-off-by: Srinivasarao Pathipati <quic_c_spathi@quicinc.com>