cursor-renderer-native: Fix hw cursor for non-square sprites
wl_shm_buffer_get_width() was used where wl_shm_buffer_get_height() should have used, resulting in only square cursors working. Make rectangular cursors work again.
wl_shm_buffer_get_width() was used where wl_shm_buffer_get_height() should have used, resulting in only square cursors working. Make rectangular cursors work again.