phy: eswin: Fix incorrect error check in probe()

phy: eswin: Fix incorrect error check in probe()

devm_ioremap() returns NULL on failure, not an ERR_PTR.
Using IS_ERR() to check the return value is incorrect.

Fix this by checking for NULL and returning -ENOMEM.

Fixes: 67ee9ccaa34a ("phy: eswin: Create eswin directory and add EIC7700 SATA PHY driver")
Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/linux-phy/adjNbuWoc1B-3Ok1@stanley.mountain/
Signed-off-by: Yulin Lu <luyulin@eswincomputing.com>
Link: https://patch.msgid.link/20260413070033.128-1-luyulin@eswincomputing.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>