Better error message in mysqlmanager

Docs/manual.texi:
  Cleanup
tools/mysqlmanager.c:
  Better error message

Docs/manual.texi

@@ -5286,6 +5286,7 @@ Replication should work with @code{RAND()} and user variables @code{@@var}.
 Online backup with very low performance penalty.  The online backup will
 make it easy to add a new replication slave without taking down the
 master.
+@item
 Allow @code{DELETE} on @code{MyISAM} tables to use the record cache.
 To do this, we need to update the threads record cache when we update
 the @code{.MYD} file.

tools/mysqlmanager.c

@@ -1170,8 +1170,8 @@ static char* read_line(struct manager_thd* thd)
     {
       if (vio_should_retry(thd->vio) && retry_count++ < MAX_RETRY_COUNT)
 	continue;
-      log_err("Error reading command from client (Error: %d)",
-	      vio_errno(thd->vio));
+      log_err("Error reading command from client (len: %d  Error: %d)",
+	      len, vio_errno(thd->vio));
       thd->fatal=1;
       return 0;
     }