llvmpipe: don't allow texture/resource swizzles on linear path

This fixes another VMware test (dx9-stretch-formats-copy-a8r8g8b8-x8r8g8b8).

Signed-off-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
cc: mesa-stable

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17062>
1 file changed