ibmvnic: fix login buffer memory leak

Commit 34f0f4e3f4 ("ibmvnic: Fix login buffer memory leaks") frees
login_rsp_buffer in release_resources() and send_login()
because handle_login_rsp() does not free it.
Commit f3ae59c0c0 ("ibmvnic: store RX and TX subCRQ handle array in
ibmvnic_adapter struct") frees login_rsp_buffer in handle_login_rsp().
It seems unnecessary to free it in release_resources() and send_login().
There are chances that handle_login_rsp returns earlier without freeing
buffers. Double-checking the buffer is harmless since
release_login_buffer and release_login_rsp_buffer will
do nothing if buffer is already freed.

Fixes: f3ae59c0c0 ("ibmvnic: store RX and TX subCRQ handle array in ibmvnic_adapter struct")
Fixes: 34f0f4e3f4 ("ibmvnic: Fix login buffer memory leaks")
Signed-off-by: Lijun Pan <ljp@linux.ibm.com>
Link: https://lore.kernel.org/r/20201219213919.21045-1-ljp@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/ibm/ibmvnic.c

@@ -955,6 +955,7 @@ static void release_resources(struct ibmvnic_adapter *adapter)
 	release_rx_pools(adapter);
 
 	release_napi(adapter);
+	release_login_buffer(adapter);
 	release_login_rsp_buffer(adapter);
 }
 
@@ -3873,7 +3874,9 @@ static int send_login(struct ibmvnic_adapter *adapter)
 		return -1;
 	}
 
+	release_login_buffer(adapter);
 	release_login_rsp_buffer(adapter);
+
 	client_data_len = vnic_client_data_len(adapter);
 
 	buffer_size =