MIPS: bpf: Add SEEN_SKB to flags when looking for the PKT_TYPE

The SKF_AD_PKTTYPE uses the skb pointer so make sure it's in the
flags so it will be initialized in time.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: netdev@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7125/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/net/bpf_jit.c

@@ -1322,6 +1322,8 @@ jmp_cmp:
 				emit_andi(r_A, r_s0, VLAN_TAG_PRESENT, ctx);
 			break;
 		case BPF_ANC | SKF_AD_PKTTYPE:
+			ctx->flags |= SEEN_SKB;
+
 			off = pkt_type_offset();
 
 			if (off < 0)