audit_receive_msg() sends uninitialized data for AUDIT_TTY_GET when
the task was not found.
Send reply only when task was found.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>