Rename kfree to kmm_free for consistency with other naming conventions

net/socket/net_poll.c

@@ -319,7 +319,7 @@ static inline int net_pollsetup(FAR struct socket *psock,
   return OK;
 
 errout_with_lock:
-  kfree(info);
+  kmm_free(info);
   net_unlock(flags);
   return ret;
 }
@@ -374,7 +374,7 @@ static inline int net_pollteardown(FAR struct socket *psock,
 
       /* Then free the poll info container */
 
-      kfree(info);
+      kmm_free(info);
     }
 
   return OK;