Updated prototype of ha_s3::write_row() to get s3 to compile

storage/maria/ha_s3.cc

@@ -239,7 +239,7 @@ void ha_s3::register_handler(MARIA_HA *file)
    When table is moved to S3, writes are not allowed.
 */
 
-int ha_s3::write_row(uchar *buf)
+int ha_s3::write_row(const uchar *buf)
 {
   if (in_alter_table)
     return ha_maria::write_row(buf);

storage/maria/ha_s3.h

@@ -30,7 +30,7 @@ class ha_s3 :public ha_maria
 
   int create(const char *name, TABLE *table_arg, HA_CREATE_INFO *ha_create_info);
   int open(const char *name, int mode, uint open_flags);
-  int write_row(uchar *buf);
+  int write_row(const uchar *buf);
   int update_row(const uchar * old_data, const uchar * new_data)
   {
     return HA_ERR_WRONG_COMMAND;