soc: aspeed: lpc: Fix impossible judgment condition

soc: aspeed: lpc: Fix impossible judgment condition

smatch error：
drivers/soc/aspeed/aspeed-lpc-snoop.c:169
aspeed_lpc_snoop_config_irq() warn: platform_get_irq() does not return zero

platform_get_irq() return non-zero IRQ number or negative error code,
change '!lpc_snoop->irq' to 'lpc_snoop->irq < 0' to fix this.

Fixes: 9f4f9ae81d0a ("drivers/misc: add Aspeed LPC snoop driver")
Signed-off-by: Su Hui <suhui@nfschina.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20231027020703.1231875-1-suhui@nfschina.com
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>