[media] em28xx-i2c: relax error check in em28xx_i2c_recv_bytes()

[media] em28xx-i2c: relax error check in em28xx_i2c_recv_bytes()

It turned out that some devices return less bytes then requested via i2c when
ALL of the following 3 conditions are met:
- i2c bus B is used
- there was no attempt to write to the specified slave address before
- no device present at the specified slave address
With the current code, this triggers an -EIO error and prints a message to the
system log.
Because it can happen very often during device probing, it is better to ignore
this error and bail out silently after the follwing i2c transaction success
check with -ENODEV.

[mchehab@redhat.com: a small CodingStyle fix]
Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>