More clang warnings that might be relevant

[jwpeterson]

src/qoi/src/absorption_coeff.C:98:39: warning: comparison of unsigned expression >= 0 is always true [-Wtautological-compare]
    for (unsigned int i=data_size-1; i>=0; i--)
                                     ~^ ~

../../src/physics/src/spalart_allmaras_stab_helper.C:91:188: warning: operator '?:' has lower precedence than '+'; '+' will be evaluated first [-Wparentheses]
    libMesh::Number inv_sigmadivnuplusnuphysicalGradnu = (1./this->_sa_params.get_sigma())*(grad_nu*grad_nu + ((nu_value + mu)*(hess_nu(0,0) + hess_nu(1,1) + (this->_flow_vars.dim() == 3)?hess_nu(2,2):0)) + this->_sa_params.get_cb2()*grad_nu*grad_nu);