plugins: Use open()/read() instead of fopen()/fread() on autopair
plugins: Use open()/read() instead of fopen()/fread() on autopair

open()/read() is more common on BlueZ code. Incidentally, get rid of
this compilation error (using gcc 4.6.3):

plugins/autopair.c: In function ‘autopair_init’:
plugins/autopair.c:154:8: error: ignoring return value of ‘fread’,
declared with attribute warn_unused_result [-Werror=unused-result]

pstglia/external-bluetooth-bluez,pkarasev3/bluez,ComputeCycles/bluez,pstglia/external-bluetooth-bluez,silent-snowman/bluez,silent-snowman/bluez,mapfau/bluez,pkarasev3/bluez,pstglia/external-bluetooth-bluez,ComputeCycles/bluez,silent-snowman/bluez,ComputeCycles/bluez,mapfau/bluez,mapfau/bluez,mapfau/bluez,ComputeCycles/bluez,pstglia/external-bluetooth-bluez,silent-snowman/bluez,pkarasev3/bluez,pkarasev3/bluez