panfrost/decode: Don't disassemble NULL shaders

It is legal to load a shader from a NULL address, particularly when the
TILER job is used strictly for effects on the Z/S buffer with 0x0 color
mask. Don't crash the decoder in this case.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
1 file changed