x86: pmc-atom: Assign debugfs node as soon as possible

pmc_dbgfs_unregister() will be called when pmc->dbgfs_dir is unconditionally
NULL on error path in pmc_dbgfs_register(). To prevent this we move the
assignment to where is should be.

Fixes: f855911 (x86/pmc_atom: Expose PMC device state and platform sleep state)
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Aubrey Li <aubrey.li@linux.intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Kumar P. Mahesh <mahesh.kumar.p@intel.com>
Link: http://lkml.kernel.org/r/1421253575-22509-2-git-send-email-andriy.shevchenko@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/pmc_atom.c

@@ -217,6 +217,8 @@ static int pmc_dbgfs_register(struct pmc_dev *pmc, struct pci_dev *pdev)
 	if (!dir)
 		return -ENOMEM;
 
+	pmc->dbgfs_dir = dir;
+
 	f = debugfs_create_file("dev_state", S_IFREG | S_IRUGO,
 				dir, pmc, &pmc_dev_state_ops);
 	if (!f) {
@@ -229,7 +231,7 @@ static int pmc_dbgfs_register(struct pmc_dev *pmc, struct pci_dev *pdev)
 		dev_err(&pdev->dev, "sleep_state register failed\n");
 		goto err;
 	}
-	pmc->dbgfs_dir = dir;
+
 	return 0;
 err:
 	pmc_dbgfs_unregister(pmc);