iommu: Remove deferred attach check from __iommu_detach_device()

iommu: Remove deferred attach check from __iommu_detach_device()

At the current moment, __iommu_detach_device() is only called via call
chains that are after the device driver is attached - eg via explicit
attach APIs called by the device driver.

Commit bd421264ed30 ("iommu: Fix deferred domain attachment") has removed
deferred domain attachment check from __iommu_attach_device() path, so it
should just unconditionally work in the __iommu_detach_device() path.

It actually looks like a bug that we were blocking detach on these paths
since the attach was unconditional and the caller is going to free the
(probably) UNAMANGED domain once this returns.

The only place we should be testing for deferred attach is during the
initial point the dma device is linked to the group, and then again
during the dma api calls.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20230110025408.667767-5-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>