This patch adds the 'level' field into the i2c_adapter structure, which is 
used to represent the 'logical' level of nesting for the purposes of 
lockdep. This field is then used in the i2c_transfer() function, to 
acquire the per-adapter bus_lock with correct nesting level.
Signed-off-by: NJiri Kosina <jikos@jikos.cz>
Signed-off-by: NJean Delvare <khali@linux-fr.org>