input: it7258_ts_i2c: clean up the it7258_ts_i2c driver

Clean it7258_ts_i2c touchscreen driver from checkpatch errors.

This patch is a propagated patch from 3.18 kernel
'commit 6b0cae0c59dc ("input: it7258_ts_i2c: clean
checkpatch errors")'

Change-Id: I7eac4a04a19beebe8c89b5328a2cf921fa78bb69
Signed-off-by: Sudhakar Manapati <smanap@codeaurora.org>
Signed-off-by: Abinaya P <abinayap@codeaurora.org>