broadcom/cle: assert attribute has a value

This assertions helps to fix several warnings detected by static
analyzer regarding passing null pointers to functions that expects
non-null pointer.

Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>
Reviewed-by: Jose Maria Casanova Crespo <jmcasanova@igalia.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34050>
1 file changed