GroupwiseRegistration::optimization doesn't make use of cost_function

[jcfr]

In the GroupwiseRegistration::optimization function, the cost_function is not used hence the warning reported below.

Indeed, if we trace the flow, there functions are called:

GroupwiseRegistration::optimization -> min_newuoa -> min_newuoa -> newuoa_ -> newuob_ -> biglag_ -> no use of "func"

void GroupwiseRegistration::optimization(void)
{
	cost_function costFunc(this);
	int prev = 0;
	int step = 1;

	while (m_degree_inc < m_degree)
	{
		nIter = 0;
		int n = (m_degree_inc + 1) * (m_degree_inc + 1) * m_nSubj * 2 - prev;
		min_newuoa(n, &m_coeff[prev], costFunc, 1.0f, 1e-5f, m_maxIter);
		prev = (m_degree_inc + 1) * (m_degree_inc + 1) * m_nSubj * 2;
		m_degree_inc = min(m_degree_inc + step, m_degree);
	}
	
	// the entire optimization together
	nIter = 0;
	min_newuoa(m_csize * 2, m_coeff, costFunc, 1.0f, 1e-6f, m_maxIter);
}

In file included from /home/jcfr/Projects/SlicerSALT-Release-Qt5/GROUPS/Modules/CLI/Groups/GroupwiseRegistration.cpp:19:0:
/home/jcfr/Projects/SlicerSALT-Release-Qt5/GROUPS/Modules/CLI/Groups/newuoa.h: In instantiation of ‘int biglag_(int, int, TYPE*, TYPE*, TYPE*, TYPE*, int*, int*, int*, TYPE*, TYPE*, TYPE*, TYPE*, TYPE*, TYPE*, TYPE*, TYPE*, Func&) [with TYPE = float; Func = cost_function]’:
/home/jcfr/Projects/SlicerSALT-Release-Qt5/GROUPS/Modules/CLI/Groups/newuoa.h:1311:10:   required from ‘TYPE newuob_(int, int, TYPE*, TYPE, TYPE, int*, int, TYPE*, TYPE*, TYPE*, TYPE*, TYPE*, TYPE*, TYPE*, TYPE*, TYPE*, TYPE*, int*, TYPE*, TYPE*, TYPE*, Func&) [with TYPE = float; Func = cost_function]’
/home/jcfr/Projects/SlicerSALT-Release-Qt5/GROUPS/Modules/CLI/Groups/newuoa.h:1709:16:   required from ‘TYPE newuoa_(int, int, TYPE*, TYPE, TYPE, int*, int, TYPE*, Func&) [with TYPE = float; Func = cost_function]’
/home/jcfr/Projects/SlicerSALT-Release-Qt5/GROUPS/Modules/CLI/Groups/newuoa.h:1720:15:   required from ‘TYPE min_newuoa(int, TYPE*, Func&, TYPE, TYPE, int) [with TYPE = float; Func = cost_function]’
/home/jcfr/Projects/SlicerSALT-Release-Qt5/GROUPS/Modules/CLI/Groups/GroupwiseRegistration.cpp:1263:65:   required from here
/home/jcfr/Projects/SlicerSALT-Release-Qt5/GROUPS/Modules/CLI/Groups/newuoa.h:59:42: warning: unused parameter ‘func’ [-Wunused-parameter]
        TYPE *gd, TYPE *s, TYPE *w, Func &func)
                                          ^

[jcfr]

Cc: @ilwoolyu @juanprietob @bpaniagua