spi: Refactor spi_stop_queue()

spi: Refactor spi_stop_queue()

The refactoring makes code less verbose and easier to read.
Besides that the binary size is also reduced, which sounds
like a win-win case:

  add/remove: 0/1 grow/shrink: 2/2 up/down: 210/-226 (-16)
  Function                            old     new   delta
  spi_destroy_queue                    42     156    +114
  spi_controller_suspend              101     197     +96
  spi_unregister_controller           346     319     -27
  spi_register_controller            1834    1794     -40
  spi_stop_queue                      159       -    -159
  Total: Before=49230, After=49214, chg -0.03%

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://msgid.link/r/20240510204945.2581944-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>