Bluetooth: Audio: Shell: Fix long/int32_t value checks

In places where we verify that the value of the long
variable does not exceed the limits of int32_t, we do
actually not need to compare the values if the two
types are the same size, which is often the case for
32-bit systems.

This fixes a variety of coverity reported issues.

Signed-off-by: Emil Gydesen <emil.gydesen@nordicsemi.no>