Input: elan_i2c - use 4-argument i2c_smbus_read_block_data()

Convert callers of i2c_smbus_read_block_data() to the 4-argument
variant, specifying the buffer size to avoid buffer overruns.

Link: https://patch.msgid.link/20261024-i2c-smbus-read-block-data-v1-4-19bb97467982@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>