NFC: llcp: Use list_for_each_entry in llcp_accept_poll

list_for_each_entry_safe() is necessary if list objects are deleted from
the list while traversing it. Not the case here, so we can use the base
list_for_each_entry variant.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>