platform/mellanox: mlxbf-tmfifo: Fix a warning message

This commit fixes the smatch static checker warning in function
mlxbf_tmfifo_rxtx_word() which complains data not initialized at
line 634 when IS_VRING_DROP() is TRUE.
Signed-off-by: Liming Sun <limings@nvidia.com>
Link: https://lore.kernel.org/r/20231012230235.219861-1-limings@nvidia.comReviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/platform/mellanox/mlxbf-tmfifo.c

@@ -609,24 +609,25 @@ static void mlxbf_tmfifo_rxtx_word(struct mlxbf_tmfifo_vring *vring,
 
 	if (vring->cur_len + sizeof(u64) <= len) {
 		/* The whole word. */
-		if (!IS_VRING_DROP(vring)) {
-			if (is_rx)
+		if (is_rx) {
+			if (!IS_VRING_DROP(vring))
 				memcpy(addr + vring->cur_len, &data,
 				       sizeof(u64));
-			else
-				memcpy(&data, addr + vring->cur_len,
-				       sizeof(u64));
+		} else {
+			memcpy(&data, addr + vring->cur_len,
+			       sizeof(u64));
 		}
 		vring->cur_len += sizeof(u64);
 	} else {
 		/* Leftover bytes. */
-		if (!IS_VRING_DROP(vring)) {
-			if (is_rx)
+		if (is_rx) {
+			if (!IS_VRING_DROP(vring))
 				memcpy(addr + vring->cur_len, &data,
 				       len - vring->cur_len);
-			else
-				memcpy(&data, addr + vring->cur_len,
-				       len - vring->cur_len);
+		} else {
+			data = 0;
+			memcpy(&data, addr + vring->cur_len,
+			       len - vring->cur_len);
 		}
 		vring->cur_len = len;
 	}