PCI: xgene-msi: Remove redundant dev_err() call in xgene_msi_probe()

devm_ioremap_resource() internally calls __devm_ioremap_resource() which
is where error checking and handling is actually taking place. i

Therefore, the dev_err() call in xgene_msi_probe() is redundant.

Remove it.

Link: https://lore.kernel.org/r/20210408132751.1198171-1-yangerkun@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: ErKun Yang <yangerkun@huawei.com>
[lorenzo.pieralisi@arm.com: commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Krzysztof Wilczyński <kw@linux.com>