iio: adc: pac1934: Fix clamped value in pac1934_reg_snapshot

iio: adc: pac1934: Fix clamped value in pac1934_reg_snapshot

The local variable 'curr_energy' was never clamped to
PAC_193X_MIN_POWER_ACC or PAC_193X_MAX_POWER_ACC because the return
value of clamp() was not used. Fix this by assigning the clamped value
back to 'curr_energy'.

Cc: stable@vger.kernel.org
Fixes: 0fb528c8255b ("iio: adc: adding support for PAC193x")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>