COMP: sampling: missing .C in Make/files

src/sampling/Make/files

@@ -43,6 +43,7 @@ surfWriters = sampledSurface/writers
 $(surfWriters)/surfaceWriter.C
 $(surfWriters)/dx/dxSurfaceWriter.C
 $(surfWriters)/ensight/ensightSurfaceWriter.C
+$(surfWriters)/ensight/ensightPTraits.C
 $(surfWriters)/foamFile/foamFileSurfaceWriter.C
 $(surfWriters)/nastran/nastranSurfaceWriter.C
 $(surfWriters)/proxy/proxySurfaceWriter.C