mptcp: remove unnecessary else statements

The 'else' statements are not needed here, because their previous 'if'
block ends with a 'return'.

This fixes CheckPatch warnings:

  WARNING: else is not generally useful after a break or return
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20240514011335.176158-7-martineau@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

net/mptcp/subflow.c

@@ -1119,6 +1119,8 @@ static enum mapping_status get_mapping_status(struct sock *ssk,
 	}
 
 	if (mpext->data_fin == 1) {
+		u64 data_fin_seq;
+
 		if (data_len == 1) {
 			bool updated = mptcp_update_rcv_data_fin(msk, mpext->data_seq,
 								 mpext->dsn64);
@@ -1131,26 +1133,26 @@ static enum mapping_status get_mapping_status(struct sock *ssk,
 				 */
 				skb_ext_del(skb, SKB_EXT_MPTCP);
 				return MAPPING_OK;
-			} else {
-				if (updated)
-					mptcp_schedule_work((struct sock *)msk);
-
-				return MAPPING_DATA_FIN;
 			}
-		} else {
-			u64 data_fin_seq = mpext->data_seq + data_len - 1;
 
-			/* If mpext->data_seq is a 32-bit value, data_fin_seq
-			 * must also be limited to 32 bits.
-			 */
-			if (!mpext->dsn64)
-				data_fin_seq &= GENMASK_ULL(31, 0);
+			if (updated)
+				mptcp_schedule_work((struct sock *)msk);
 
-			mptcp_update_rcv_data_fin(msk, data_fin_seq, mpext->dsn64);
-			pr_debug("DATA_FIN with mapping seq=%llu dsn64=%d",
-				 data_fin_seq, mpext->dsn64);
+			return MAPPING_DATA_FIN;
 		}
 
+		data_fin_seq = mpext->data_seq + data_len - 1;
+
+		/* If mpext->data_seq is a 32-bit value, data_fin_seq must also
+		 * be limited to 32 bits.
+		 */
+		if (!mpext->dsn64)
+			data_fin_seq &= GENMASK_ULL(31, 0);
+
+		mptcp_update_rcv_data_fin(msk, data_fin_seq, mpext->dsn64);
+		pr_debug("DATA_FIN with mapping seq=%llu dsn64=%d",
+			 data_fin_seq, mpext->dsn64);
+
 		/* Adjust for DATA_FIN using 1 byte of sequence space */
 		data_len--;
 	}