tg3: Increase buffer size for IRQ label

tg3: Increase buffer size for IRQ label

GCC is not happy with the current code, e.g.:

.../tg3.c:11313:37: error: ‘-txrx-’ directive output may be truncated writing 6 bytes into a region of size between 1 and 16 [-Werror=format-truncation=]
11313 |                                  "%s-txrx-%d", tp->dev->name, irq_num);
      |                                     ^~~~~~
.../tg3.c:11313:34: note: using the range [-2147483648, 2147483647] for directive argument
11313 |                                  "%s-txrx-%d", tp->dev->name, irq_num);

When `make W=1` is supplied, this prevents kernel building. Fix it by
increasing the buffer size for IRQ label and use sizeoF() instead of
hard coded constants.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Michael Chan <michael.chan@broadcom.com>
Message-ID: <20241016090647.691022-1-andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>