patch 9.0.0318: clearing screen causes flicker

Problem:    Clearing screen causes flicker.
Solution:   Do not clear but redraw in more cases.  Add () to "wait_return".

src/if_cscope.c

@@ -2474,7 +2474,7 @@ cs_show(exarg_T *eap UNUSED)
 	}
     }
 
-    wait_return(TRUE);
+    wait_return(FALSE);
     return CSCOPE_SUCCESS;
 }