drm/ttm: fix unused function warning

ttm_pool_type_count() is not used when debugfs is disabled:

drivers/gpu/drm/ttm/ttm_pool.c:243:21: error: unused function 'ttm_pool_type_count' [-Werror,-Wunused-function]
static unsigned int ttm_pool_type_count(struct ttm_pool_type *pt)

Move the definition into the #ifdef block.

Fixes: d099fc8f ("drm/ttm: new TT backend allocation pool v3")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Martin Peres <martin.peres@mupuf.org>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/405695/Signed-off-by: Christian König <christian.koenig@amd.com>

drivers/gpu/drm/ttm/ttm_pool.c

@@ -239,21 +239,6 @@ static struct page *ttm_pool_type_take(struct ttm_pool_type *pt)
 	return p;
 }
 
-/* Count the number of pages available in a pool_type */
-static unsigned int ttm_pool_type_count(struct ttm_pool_type *pt)
-{
-	unsigned int count = 0;
-	struct page *p;
-
-	spin_lock(&pt->lock);
-	/* Only used for debugfs, the overhead doesn't matter */
-	list_for_each_entry(p, &pt->pages, lru)
-		++count;
-	spin_unlock(&pt->lock);
-
-	return count;
-}
-
 /* Initialize and add a pool type to the global shrinker list */
 static void ttm_pool_type_init(struct ttm_pool_type *pt, struct ttm_pool *pool,
 			       enum ttm_caching caching, unsigned int order)
@@ -543,6 +528,20 @@ void ttm_pool_fini(struct ttm_pool *pool)
 EXPORT_SYMBOL(ttm_pool_fini);
 
 #ifdef CONFIG_DEBUG_FS
+/* Count the number of pages available in a pool_type */
+static unsigned int ttm_pool_type_count(struct ttm_pool_type *pt)
+{
+	unsigned int count = 0;
+	struct page *p;
+
+	spin_lock(&pt->lock);
+	/* Only used for debugfs, the overhead doesn't matter */
+	list_for_each_entry(p, &pt->pages, lru)
+		++count;
+	spin_unlock(&pt->lock);
+
+	return count;
+}
 
 /* Dump information about the different pool types */
 static void ttm_pool_debugfs_orders(struct ttm_pool_type *pt,