amd-xgbe: Avoid potential string truncation in name

Build with W=1 were warning about a potential string truncation:

drivers/net/ethernet/amd/xgbe/xgbe-drv.c: In function 'xgbe_alloc_channels':
drivers/net/ethernet/amd/xgbe/xgbe-drv.c:211:73: warning: '%u' directive output may be truncated writing between 1 and 10 bytes into a region of size 8 [-Wformat-truncation=]
  211 |                 snprintf(channel->name, sizeof(channel->name), "channel-%u", i);
      |                                                                         ^~
drivers/net/ethernet/amd/xgbe/xgbe-drv.c:211:64: note: directive argument in the range [0, 4294967294]
  211 |                 snprintf(channel->name, sizeof(channel->name), "channel-%u", i);
      |                                                                ^~~~~~~~~~~~
drivers/net/ethernet/amd/xgbe/xgbe-drv.c:211:17: note: 'snprintf' output between 10 and 19 bytes into a destination of size 16
  211 |                 snprintf(channel->name, sizeof(channel->name), "channel-%u", i);
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Increase the size of the "name" buffer to handle the full format range.

Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Cc: Shyam Sundar S K <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Paolo Abeni <[email protected]>
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
Signed-off-by: NipaLocal <nipa@local>

Author: kees

drivers/net/ethernet/amd/xgbe/xgbe.h

@@ -495,7 +495,7 @@ struct xgbe_ring {
  * a DMA channel.
  */
 struct xgbe_channel {
-	char name[16];
+	char name[20];
 
 	/* Address of private data area for device */
 	struct xgbe_prv_data *pdata;