iio: frequency: admv1013: remove the always true condition

unsigned int variable is always greater than or equal to zero. Make the
if condition simple.
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Fixes: da35a7b5 ("iio: frequency: admv1013: add support for ADMV1013")
Link: https://lore.kernel.org/r/YdS3gJYtECMaDDjA@debian-BULLSEYE-live-builder-AMD64Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/frequency/admv1013.c

@@ -348,7 +348,7 @@ static int admv1013_update_mixer_vgate(struct admv1013_state *st)
 
 	vcm = regulator_get_voltage(st->reg);
 
-	if (vcm >= 0 && vcm < 1800000)
+	if (vcm < 1800000)
 		mixer_vgate = (2389 * vcm / 1000000 + 8100) / 100;
 	else if (vcm > 1800000 && vcm < 2600000)
 		mixer_vgate = (2375 * vcm / 1000000 + 125) / 100;