i2c: i2c-eg20t: do not print error message in syslog if no ACK received

Using the i2c-eg20t driver and call i2cdetect or probe on the bus,
the driver will print a lot of error messages if there was no ACK
received.

i2cdetect normally print a table with all the available devices. If there
is no device on the address, the table will be empty.
Currently with the i2c-eg20t driver, the table is not visible because
the error messages destroy the table.

Error message: pch_i2c_getack return -71

This patch prevent the driver to print the messages to syslog.
The pch_i2c_wait_for_check_xfer function is the only one who is
calling pch_i2c_getack, so we can delete the function and add the
read to pch_i2c_wait_for_check_xfer.
If no ACK is received, the Message will be printed as a dbg
message.

Fixed print message to be a one liner so we can grep for the
error message.

Tested on Intel Atom E6xx and Eg20t Chipset.

Signed-off-by: Andreas Werner <wernerandy@gmx.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>