PCI: sysfs: Fix failure path for addition of "vpd" attribute

PCI: sysfs: Fix failure path for addition of "vpd" attribute

commit 0f12a4e29368a9476076515881d9ef4e5876c6e2 upstream.

Commit 280c73d ("PCI: centralize the capabilities code in
pci-sysfs.c") changed the initialisation of the "rom" and "vpd"
attributes, and made the failure path for the "vpd" attribute
incorrect.  We must free the new attribute structure (attr), but
instead we currently free dev->vpd->attr.  That will normally be NULL,
resulting in a memory leak, but it might be a stale pointer, resulting
in a double-free.

Found by inspection; compile-tested only.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andi Kleen <ak@linux.intel.com>