commit 5a9e0ffc upstream.

skb can be NULL and may lead to a NULL pointer error.

Add a check condition before setting HCI rx buffer.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>