firmware: stratix10-svc: Fix an NULL vs IS_ERR() bug in probe

firmware: stratix10-svc: Fix an NULL vs IS_ERR() bug in probe

commit dd218433f2b635d97e8fda3eed047151fd528ce4 upstream.

The devm_memremap() function returns error pointers.
It never returns NULL. Fix the check.

Fixes: 7ca5ce896524 ("firmware: add Intel Stratix10 service layer driver")
Cc: stable@vger.kernel.org
Signed-off-by: Wang Ming <machel@vivo.com>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
Link: https://lore.kernel.org/r/20230727193750.983795-1-dinguyen@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>