unix.7: Use sizeof consistently

Use ``sizeof`` consistently through all the examples in the following
way:

- Use the name of the variable instead of its type as argument for
  ``sizeof``.

	Rationale:
	https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory

Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man7/unix.7

@@ -948,7 +948,7 @@ main(int argc, char *argv[])
      * the structure.
      */
 
-    memset(&name, 0, sizeof(struct sockaddr_un));
+    memset(&name, 0, sizeof(name));
 
     /* Bind socket to socket name. */
 
@@ -956,7 +956,7 @@ main(int argc, char *argv[])
     strncpy(name.sun_path, SOCKET_NAME, sizeof(name.sun_path) \- 1);
 
     ret = bind(connection_socket, (const struct sockaddr *) &name,
-               sizeof(struct sockaddr_un));
+               sizeof(name));
     if (ret == \-1) {
         perror("bind");
         exit(EXIT_FAILURE);
@@ -1082,7 +1082,7 @@ main(int argc, char *argv[])
      * the structure.
      */
 
-    memset(&addr, 0, sizeof(struct sockaddr_un));
+    memset(&addr, 0, sizeof(addr));
 
     /* Connect socket to socket address */
 
@@ -1090,7 +1090,7 @@ main(int argc, char *argv[])
     strncpy(addr.sun_path, SOCKET_NAME, sizeof(addr.sun_path) \- 1);
 
     ret = connect(data_socket, (const struct sockaddr *) &addr,
-                   sizeof(struct sockaddr_un));
+                   sizeof(addr));
     if (ret == \-1) {
         fprintf(stderr, "The server is down.\en");
         exit(EXIT_FAILURE);