patch 8.2.3955: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move more errors to errors.h.
diff --git a/src/spellfile.c b/src/spellfile.c
index 14ea7ab..03da272 100644
--- a/src/spellfile.c
+++ b/src/spellfile.c
@@ -6240,7 +6240,7 @@
 	    buf = NULL;
 	if (buf != NULL && bufIsChanged(buf))
 	{
-	    emsg(_(e_bufloaded));
+	    emsg(_(e_file_is_loaded_in_another_buffer));
 	    vim_free(fnamebuf);
 	    return;
 	}