drm/xe: Fix xe_pm_runtime_get_if_in_use documentation

Let's be clear on what it is actually doing and align with
xe_pm_runtime_get_if_active doc style.
Tested-by: Francois Dugast <francois.dugast@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240522170105.327472-2-rodrigo.vivi@intel.comSigned-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/xe/xe_pm.c

@@ -514,10 +514,11 @@ bool xe_pm_runtime_get_if_active(struct xe_device *xe)
 }
 
 /**
- * xe_pm_runtime_get_if_in_use - Get a runtime_pm reference and resume if needed
+ * xe_pm_runtime_get_if_in_use - Get a new reference if device is active with previous ref taken
  * @xe: xe device instance
  *
- * Returns: True if device is awake and the reference was taken, false otherwise.
+ * Return: True if device is awake, a previous reference had been already taken,
+ * and a new reference was now taken, false otherwise.
  */
 bool xe_pm_runtime_get_if_in_use(struct xe_device *xe)
 {