intel/fs: Simplify check in can_propagate_from

The larger predicate here already requires that inst->opcode must be
BRW_OPCODE_MOV, so it can't BRW_OPCODE_SEL. With that removed, the
other simplifications are pretty straight forward.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25091>

src/intel/compiler/brw_fs_copy_propagation.cpp

@@ -1140,8 +1140,7 @@ can_propagate_from(fs_inst *inst)
            inst->src[0].type == inst->dst.type &&
            !inst->saturate &&
            /* Subset of !is_partial_write() conditions. */
-           !((inst->predicate && inst->opcode != BRW_OPCODE_SEL) ||
-             !inst->dst.is_contiguous())) ||
+           !inst->predicate && inst->dst.is_contiguous()) ||
           is_identity_payload(FIXED_GRF, inst);
 }