[GRASS-git] [OSGeo/grass] c3845b: r.geomorphon: fix -Wextra compiler warning (#2754)

[Nicklas Larsson]

  Branch: refs/heads/main
  Home:   https://github.com/OSGeo/grass
  Commit: c3845b2a58a588bc2ac14ca03b198e846cf8dc8f
      https://github.com/OSGeo/grass/commit/c3845b2a58a588bc2ac14ca03b198e846cf8dc8f
  Author: Nicklas Larsson <n_larsson at yahoo.com>
  Date:   2023-01-18 (Wed, 18 Jan 2023)

  Changed paths:
    M raster/r.geomorphon/geom.c
    M raster/r.geomorphon/local_proto.h

  Log Message:
  -----------
  r.geomorphon: fix -Wextra compiler warning (#2754)

The warning issued:
"warning: ordered comparison of pointer with integer zero [-Wextra]"
referring to `pattern->distance > 0`.

In addition changes unused return type int to void for radial2cartesian()