i2c: octeon: thunderx: Remove double-check after interrupt

Commit 1bb1ff3e ("i2c: octeon: Improve performance if interrupt is
early") added a double-check around the wait_event_timeout() condition.
The performance problem that this commit tried to work-around
could not be reproduced. It also makes the wait condition more
complicated then it should be. Therefore remove the double-check.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>