Staging: iio: Remove unnecessory immediate else after return statement

This patch fixes following checkpatch.pl warning:

WARNING: else is not generally useful after a break or return

Signed-off-by: Vaishali Thakkar <vthakkar1994@gmail.com>
Acked-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>