small fixes for issues detected by coverity (thanks Nico!)

Geo/ChainComplex.cpp

Geo/ExtrudeParams.cpp

Geo/GFace.cpp

Geo/GFaceCompound.cpp

Geo/GModelFactory.cpp

Geo/GModelIO_CELUM.cpp

Geo/GModelIO_MSH2.cpp

Geo/GModelIO_PLY.cpp

Geo/GModelIO_SU2.cpp

Geo/Geo.cpp

Geo/Homology.cpp

Geo/findLinks.cpp

Mesh/CenterlineField.cpp

Mesh/DivideAndConquer.h

Mesh/meshGFace.cpp

Mesh/meshGFaceOptimize.cpp

Mesh/meshGFaceOptimize.h

Mesh/meshGFaceTransfinite.cpp

Mesh/meshGRegion.cpp

Numeric/MetricBasis.cpp