isl: Remove useless qualifier from return type.

Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>

src/intel/isl/isl_surface_state.c

@@ -90,7 +90,7 @@ static const uint32_t isl_to_gen_multisample_layout[] = {
 };
 #endif
 
-static const uint8_t
+static uint8_t
 get_surftype(enum isl_surf_dim dim, isl_surf_usage_flags_t usage)
 {
    switch (dim) {