iommu/vt-d: Fix a potential memory leak

BugLink: http://bugs.launchpad.net/bugs/1768429

commit bbe4b3af upstream.

A memory block was allocated in intel_svm_bind_mm() but never freed
in a failure path. This patch fixes this by free it to avoid memory
leakage.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: <stable@vger.kernel.org> # v4.4+
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Fixes: 2f26e0a9 ('iommu/vt-d: Add basic SVM PASID support')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/iommu/intel-svm.c

@@ -389,6 +389,7 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
 				pasid_max - 1, GFP_KERNEL);
 		if (ret < 0) {
 			kfree(svm);
+			kfree(sdev);
 			goto out;
 		}
 		svm->pasid = ret;