drm/radeon: fix logic inversion in radeon_sync_resv

Shared is the opposite of write/exclusive.

Signed-off-by: Christian König <christian.koenig@amd.com>
Fixes: 0597ca7b ("drm/radeon: use new iterator in radeon_sync_resv")
Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1970


Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220412093626.608767-1-christian.koenig@amd.com