staging: iio: resolver: add missing braces on if-else statements

Add braces around the else clause to adhere to kernel coding style. This
clears the following checkpatch issue:

CHECK: braces {} should be used on all arms of this statement

Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>