Remove spaces from sim3 type names

Discovered while experimenting with g2o cli utility.
Spaces introduced by clang-format in a70b6d7 prevent
these types from being parsable from a file.

Several similar fixes were already applied to other types
(e.g. e28160d and 25e393e), but types/sim were missed
on those occasions.

g2o/types/sim3/types_seven_dof_expmap.cpp

@@ -34,11 +34,12 @@ namespace g2o {
 G2O_USE_TYPE_GROUP(sba);
 G2O_REGISTER_TYPE_GROUP(sim3);
 
-G2O_REGISTER_TYPE(VERTEX_SIM3 : EXPMAP, VertexSim3Expmap);
-G2O_REGISTER_TYPE(EDGE_SIM3 : EXPMAP, EdgeSim3);
-G2O_REGISTER_TYPE(EDGE_PROJECT_SIM3_XYZ : EXPMAP, EdgeSim3ProjectXYZ);
-G2O_REGISTER_TYPE(EDGE_PROJECT_INVERSE_SIM3_XYZ
-                  : EXPMAP, EdgeInverseSim3ProjectXYZ);
+// clang-format off
+G2O_REGISTER_TYPE(VERTEX_SIM3:EXPMAP, VertexSim3Expmap);
+G2O_REGISTER_TYPE(EDGE_SIM3:EXPMAP, EdgeSim3);
+G2O_REGISTER_TYPE(EDGE_PROJECT_SIM3_XYZ:EXPMAP, EdgeSim3ProjectXYZ);
+G2O_REGISTER_TYPE(EDGE_PROJECT_INVERSE_SIM3_XYZ:EXPMAP, EdgeInverseSim3ProjectXYZ);
+// clang-format on
 
 VertexSim3Expmap::VertexSim3Expmap() : BaseVertex<7, Sim3>() {
   _marginalized = false;