patch 8.2.3967: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move more errors to errors.h.
diff --git a/src/if_cscope.c b/src/if_cscope.c
index d587587..c7bd9e3 100644
--- a/src/if_cscope.c
+++ b/src/if_cscope.c
@@ -1176,7 +1176,7 @@
 
 	f = mch_fopen((char *)tmp, "w");
 	if (f == NULL)
-	    semsg(_(e_notopen), tmp);
+	    semsg(_(e_cant_open_file_str), tmp);
 	else
 	{
 	    cs_file_results(f, nummatches);