intel_th: Fix a double put_device() in error path

Commit a753bfc ("intel_th: Make the switch allocate its subdevices")
factored out intel_th_subdevice_alloc() from intel_th_populate(), but got
the error path wrong, resulting in two instances of a double put_device()
on a freshly initialized, but not 'added' device.

Fix this by only doing one put_device() in the error path.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Fixes: a753bfc ("intel_th: Make the switch allocate its subdevices")
Reported-by: Wen Yang <wenyang@linux.alibaba.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: stable@vger.kernel.org # v4.14+
Link: https://lore.kernel.org/r/20191120130806.44028-2-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwtracing/intel_th/core.c

@@ -649,10 +649,8 @@ intel_th_subdevice_alloc(struct intel_th *th,
 	}
 
 	err = intel_th_device_add_resources(thdev, res, subdev->nres);
-	if (err) {
-		put_device(&thdev->dev);
+	if (err)
 		goto fail_put_device;
-	}
 
 	if (subdev->type == INTEL_TH_OUTPUT) {
 		if (subdev->mknode)
@@ -667,10 +665,8 @@ intel_th_subdevice_alloc(struct intel_th *th,
 	}
 
 	err = device_add(&thdev->dev);
-	if (err) {
-		put_device(&thdev->dev);
+	if (err)
 		goto fail_free_res;
-	}
 
 	/* need switch driver to be loaded to enumerate the rest */
 	if (subdev->type == INTEL_TH_SWITCH && !req) {