samples/bpf: Remove unneeded variable

Return value directly instead of taking this in another redundant variable.
Reported-by: Zeal Robot <zealci@zte.com.cm>
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211209080051.421844-1-chi.minghao@zte.com.cn

samples/bpf/xdp_redirect_cpu.bpf.c

@@ -100,7 +100,6 @@ u16 get_dest_port_ipv4_udp(struct xdp_md *ctx, u64 nh_off)
 	void *data     = (void *)(long)ctx->data;
 	struct iphdr *iph = data + nh_off;
 	struct udphdr *udph;
-	u16 dport;
 
 	if (iph + 1 > data_end)
 		return 0;
@@ -111,8 +110,7 @@ u16 get_dest_port_ipv4_udp(struct xdp_md *ctx, u64 nh_off)
 	if (udph + 1 > data_end)
 		return 0;
 
-	dport = bpf_ntohs(udph->dest);
-	return dport;
+	return bpf_ntohs(udph->dest);
 }
 
 static __always_inline