Simple conditions without negations inflict less cognitive load
on readers.

Rework conditional branches not to use negations. Also add braces
around single statement branches where their counterpart else-branches
consist of more than one statement as suggested in the paragraph 3 of
the coding style.
Suggested-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NDmitry Rozhkov <dmitry.rozhkov@linux.intel.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>