bpf: fix DROP_MISSED_TAIL_CALL warnings emitted by coccicheck

The coccicheck has been silently failing for a while [1], and the CI was
recently fixed for the v1.13 branch bumping the related docker image in
100b580.

The check currently complains about two missing DROP_MISSED_TAIL_CALL
occurrences in bpf/lib/nodeport.h, although we do actually return it
(but indirectly). Let's make it more explicit, so that the check no
longer emits a warning.

[1]: 0dad157 ("cocci: Fix Python path for coccilib")

Related: 279bbdc ("bpf: Return DROP_MISSED_TAIL_CALL when missing some tail calls")
Signed-off-by: Marco Iorio <marco.iorio@isovalent.com>

bpf/lib/nodeport.h

@@ -1028,7 +1028,7 @@ static __always_inline int nodeport_lb6(struct __ctx_buff *ctx,
 			if (dsr) {
 				ctx_store_meta(ctx, CB_SRC_LABEL, src_identity);
 				ep_tail_call(ctx, CILIUM_CALL_IPV6_NODEPORT_DSR_INGRESS);
-				ret = DROP_MISSED_TAIL_CALL;
+				return DROP_MISSED_TAIL_CALL;
 			}
 
 			if (IS_ERR(ret))
@@ -2262,7 +2262,7 @@ static __always_inline int nodeport_lb4(struct __ctx_buff *ctx,
 			if (dsr) {
 				ctx_store_meta(ctx, CB_SRC_LABEL, src_identity);
 				ep_tail_call(ctx, CILIUM_CALL_IPV4_NODEPORT_DSR_INGRESS);
-				ret = DROP_MISSED_TAIL_CALL;
+				return DROP_MISSED_TAIL_CALL;
 			}
 
 			if (IS_ERR(ret))