pipe_loader_sw: Fix fd leak when instantiated via pipe_loader_sw_probe_kms

pipe_loader_sw: Fix fd leak when instantiated via pipe_loader_sw_probe_kms

Make pipe_loader_sw_probe_kms take ownership of the passed in fd,
like pipe_loader_drm_probe_fd does.

The only caller is dri_kms_init_screen which passes in a dupped fd,
just like dri2_init_screen passes in a dupped fd to
pipe_loader_drm_probe_fd.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>