gbm: fix typo in doxygen comment

This fixes the misspelling of gbm_bo_import api param.

Signed-off-by: Mun Gwan-gyeong <elongbug@gmail.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>

src/gbm/main/gbm.c

@@ -426,8 +426,8 @@ gbm_bo_create_with_modifiers(struct gbm_device *gbm,
  * independent of the foreign object.
  *
  * \param gbm The gbm device returned from gbm_create_device()
- * \param gbm The type of object we're importing
- * \param gbm Pointer to the external object
+ * \param type The type of object we're importing
+ * \param buffer Pointer to the external object
  * \param usage The union of the usage flags for this buffer
  *
  * \return A newly allocated buffer object that should be freed with