emul_sbs_gauge: Don't set bad val in i2c msg buf

The SBS Gauge emulator would set the I2C buffer message with a value from
the emulator's custom read function even on a read error instead of just
returning. This behavior may be improperly relied upon by future tests.

Return early on register read before setting the i2c message buffer value
in the emulator.

Signed-off-by: Aaron Massey <aaronmassey@google.com>
1 file changed