watchdog: pic32-wdt: Fix return value check in pic32_wdt_drv_probe()

In case of error, the function devm_ioremap() returns NULL pointer
not ERR_PTR(). The IS_ERR() test in the return value check should
be replaced with NULL test.

Signed-off-by: Wei Yongjun <[e-mail]>
Reviewed-by: Guenter Roeck <[e-mail]>
Signed-off-by: Guenter Roeck <[e-mail]>
Signed-off-by: Wim Van Sebroeck <[e-mail]>

drivers/watchdog/pic32-wdt.c

···
 		return PTR_ERR(wdt->regs);
 
 	wdt->rst_base = devm_ioremap(&pdev->dev, PIC32_BASE_RESET, 0x10);
-	if (IS_ERR(wdt->rst_base))
-		return PTR_ERR(wdt->rst_base);
+	if (!wdt->rst_base)
+		return -ENOMEM;
 
 	wdt->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(wdt->clk)) {