ice: remove unnecessary duplicated AQ command flag setting

Commit a012dca9 ("ice: add ethtool -m support for reading i2c eeprom
modules") unnecessarily added the ICE_AQ_FLAG_BUF flag to the descriptor
when sending the indirect Read/Write SFF EEPROM AQ command. The flag is
already added later in the code flow for all indirect AQ commands, i.e.
commands that provide an additional data buffer.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>