patch 8.2.3959: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move more errors to errors.h.
diff --git a/src/ex_eval.c b/src/ex_eval.c
index 337f1ed..cb3fbc6 100644
--- a/src/ex_eval.c
+++ b/src/ex_eval.c
@@ -2516,15 +2516,15 @@
 }
 
 /*
- * ":endfunction" when not after a ":function"
+ * ":endfunction" or ":enddef" when not after a ":function"
  */
     void
 ex_endfunction(exarg_T *eap)
 {
     if (eap->cmdidx == CMD_enddef)
-	emsg(_("E193: :enddef not inside a function"));
+	semsg(_(e_str_not_inside_function), ":enddef");
     else
-	emsg(_("E193: :endfunction not inside a function"));
+	semsg(_(e_str_not_inside_function), ":endfunction");
 }
 
 /*