mwifiex: minor corrections in multiport aggregation code

This patch includes below changes
1) Check if multiport aggregation feature flag while doing rx
length validation check.
2) Reset buffer size variables when buffers are freed.
Signed-off-by: Xinming Hu <huxm@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/mwifiex/sdio.c

@@ -1606,8 +1606,9 @@ static int mwifiex_process_int_status(struct mwifiex_adapter *adapter)
 				(rx_len + MWIFIEX_SDIO_BLOCK_SIZE -
 				 1) / MWIFIEX_SDIO_BLOCK_SIZE;
 			if (rx_len <= INTF_HEADER_LEN ||
-			    (rx_blocks * MWIFIEX_SDIO_BLOCK_SIZE) >
-			     card->mpa_rx.buf_size) {
+			    (card->mpa_rx.enabled &&
+			     ((rx_blocks * MWIFIEX_SDIO_BLOCK_SIZE) >
+			      card->mpa_rx.buf_size))) {
 				mwifiex_dbg(adapter, ERROR,
 					    "invalid rx_len=%d\n",
 					    rx_len);
@@ -1925,6 +1926,8 @@ static int mwifiex_alloc_sdio_mpa_buffers(struct mwifiex_adapter *adapter,
 	if (ret) {
 		kfree(card->mpa_tx.buf);
 		kfree(card->mpa_rx.buf);
+		card->mpa_tx.buf_size = 0;
+		card->mpa_rx.buf_size = 0;
 	}
 
 	return ret;