Cleanup of MDEV-14974: --port ignored for --host=localhost

The old code added to 10.6 was inconsisting in how TCP/IP and
socket connection was chosen. One got also a confusing warning
in some cases.

Examples:
> ../client/mysql --print-defaults
../client/mysql would have been started with the following arguments:
--socket=/tmp/mariadbd.sock --port=3307 --no-auto-rehash
> ../client/mysql
ERROR 2002 (HY000): Can't connect to local server through socket '/tmp/mariadbd.sock' (2)
> ../client/mysql --print-defaults
../client/mysql would have been started with the following arguments:
--socket=/tmp/mariadbd.sock --port=3307 --no-auto-rehash
> ../client/mysql --port=3333
WARNING: Forcing protocol to  TCP  due to option specification. Please explicitly state intended protocol.
ERROR 2002 (HY000): Can't connect to server on 'localhost' (111)
> ../client/mysql --port=3333 --socket=sss
ERROR 2002 (HY000): Can't connect to local server through socket 'sss' (2)
> ../client/mysql --socket=sss --port=3333
ERROR 2002 (HY000): Can't connect to local server through socket 'sss' (2)

Some notable things:
- One gets a warning if one uses just --port if config file sets socket
- Using port and socket gives no warning
- Using socket and then port still uses socket

This patch changes things the following ways:
If --port= is given on the command line, the the protocol is automatically
  changed to "TCP/IP".
- If --socket= is given on the command line, the protocol is automatically
  changed to "socket".
- The last option wins
- No warning is given if protocol changes automatically.

client/client_priv.h

@@ -148,51 +148,3 @@ enum options_client
 #else
 #define SOCKET_PROTOCOL_TO_FORCE MYSQL_PROTOCOL_PIPE
 #endif
-
-/**
-  Utility function to implicitly change the connection protocol to a
-  consistent value given the command line arguments.  Additionally,
-  warns the user that the protocol has been changed.
-
-  Arguments:
-    @param [in] host              Name of the host to connect to
-    @param [in, out] opt_protocol Location of the protocol option
-                                  variable to update
-    @param [in] new_protocol      New protocol to force
-*/
-static inline void warn_protocol_override(char *host,
-                                          uint *opt_protocol,
-                                          uint new_protocol)
-{
-  DBUG_ASSERT(new_protocol == MYSQL_PROTOCOL_TCP
-      || new_protocol == SOCKET_PROTOCOL_TO_FORCE);
-
-
-  if ((host == NULL
-        || strncmp(host, LOCAL_HOST, sizeof(LOCAL_HOST)-1) == 0))
-  {
-    const char *protocol_name;
-
-    if (*opt_protocol == MYSQL_PROTOCOL_DEFAULT
-#ifndef _WIN32
-        && new_protocol == MYSQL_PROTOCOL_SOCKET
-#else
-        && new_protocol == MYSQL_PROTOCOL_TCP
-#endif
-    )
-    {
-      /* This is already the default behavior, do nothing */
-      return;
-    }
-
-    protocol_name= sql_protocol_typelib.type_names[new_protocol-1];
-
-    fprintf(stderr, "%s %s %s\n",
-        "WARNING: Forcing protocol to ",
-        protocol_name,
-        " due to option specification. "
-          "Please explicitly state intended protocol.");
-
-    *opt_protocol = new_protocol;
-  }
-}