drm/i2c: tda9950: fix timeout counter check

Currently the check to see if the timeout has reached zero is incorrect
and the check is instead checking if the timeout is non-zero and not
zero, hence it will break out of the loop on the first iteration and
the msleep is never executed.  Fix this by breaking from the loop when
timeout is zero.

Detected by CoverityScan, CID#1469404 ("Logically Dead Code")

Fixes: f0316f93

 ("drm/i2c: tda9950: add CEC driver")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>