tools:iio: adjust coding style

Fix various coding style issues, including:
  * have spaces around operators
  * indentation
  * consolidate parameters in same line
  * required braces
  * adjust/drop comments
  * multiline comment style
  * delete unnecessary empty lines
  * add empty lines to visualize logial code blocks
  * typos

Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>