tree-wide: make ++/-- usage consistent WRT spacing

Throughout the tree there's spurious use of spaces separating ++ and --
operators from their respective operands.  Make ++ and -- operator
consistent with the majority of existing uses; discard the spaces.

src/machine/machinectl.c

@@ -180,7 +180,7 @@ static int list_machines(int argc, char *argv[], void *userdata) {
                 if (l > max_service)
                         max_service = l;
 
-                n_machines ++;
+                n_machines++;
         }
         if (r < 0)
                 return bus_log_parse_error(r);
@@ -2236,7 +2236,7 @@ static int list_transfers(int argc, char *argv[], void *userdata) {
                 if (id > max_id)
                         max_id = id;
 
-                n_transfers ++;
+                n_transfers++;
         }
         if (r < 0)
                 return bus_log_parse_error(r);