Bluetooth: ipsp: Fix checking for NULL pointer

This may cause static analyser error such as the following:

  Null-checking "tmp" suggests that it may be null, but it has already
  been dereferenced on all paths leading to the check.
             if (tmp) {

Change-Id: Id04f8d052d8128003d5b91f7a8303940529ef261
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>