pkg-config: Don't traceback when not found and not required
pkg-config: Don't traceback when not found and not required

.get_command() will return None when it's not found, so there's no
point trying to print that. Print self.name instead, which is what
we tried to search for.

mesonbuild/meson,becm/meson,mesonbuild/meson,pexip/meson,mesonbuild/meson,QuLogic/meson,jpakkane/meson,becm/meson,pexip/meson,mesonbuild/meson,jpakkane/meson,QuLogic/meson,mesonbuild/meson,becm/meson,QuLogic/meson,QuLogic/meson,QuLogic/meson,becm/meson,mesonbuild/meson,mesonbuild/meson,pexip/meson,mesonbuild/meson,mesonbuild/meson,becm/meson,jpakkane/meson,QuLogic/meson,becm/meson,pexip/meson,becm/meson,jpakkane/meson,pexip/meson,pexip/meson,jpakkane/meson,mesonbuild/meson,becm/meson,QuLogic/meson,jpakkane/meson,pexip/meson,pexip/meson,QuLogic/meson,jpakkane/meson,jpakkane/meson,jpakkane/meson,pexip/meson,QuLogic/meson,becm/meson,becm/meson,pexip/meson