Patch for 4.9.y: (8250_pci: Fix potential use-after-free in error path)

[Sumit Semwal <sumit.semwal@xxxxxxxxxx>]

Hello,

For 4.9.y, please review

Upstream commit : c130b666a9a711f985a0a44b58699ebe14bb7245
Subject: 8250_pci: Fix potential use-after-free in error path
Applicable to: 4.9 stable kernel

This fixes Commit f209fa03fc9d ("serial: 8250_pci: Detach low-level
driver during
PCI error recovery") that introduces a potential use-after-free in the
error path.

Best regards,
Sumit.