powerpc/4xx: Fix return value check in hsta_msi_probe()
powerpc/4xx: Fix return value check in hsta_msi_probe()

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

Signed-off-by: Wei Yongjun <b8f9cab8be13de37b9588aedad10a20fc3a68783@trendmicro.com.cn>
Signed-off-by: Michael Ellerman <864f124608374e06e4da1fa5d2e47ed839b95411@ellerman.id.au>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs