xc2par: Remove some unnecessary mut's
xc2par: Remove some unnecessary mut's

azonenberg/openfpga,azonenberg/openfpga,azonenberg/openfpga,rqou/openfpga,rqou/openfpga,azonenberg/openfpga,azonenberg/openfpga,rqou/openfpga,rqou/openfpga,rqou/openfpga