patch 8.2.4005: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move more error messages to errors.h.
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index b76de2d..445e4ee 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -8273,7 +8273,7 @@
 {
     if (vim_mkdir(name, prot) != 0)
     {
-	semsg(_("E739: Cannot create directory: %s"), name);
+	semsg(_(e_cannot_create_directory_str), name);
 	return FAIL;
     }
     return OK;