regmap: debugfs: Don't leak dummy names

When allocating dummy names we need to store a pointer to the string we
allocate so that we don't leak it on free.

Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c
index e3e7b91..dd3a168 100644
--- a/drivers/base/regmap/regmap-debugfs.c
+++ b/drivers/base/regmap/regmap-debugfs.c
@@ -575,7 +575,9 @@
 	}
 
 	if (!strcmp(name, "dummy")) {
-		name = kasprintf(GFP_KERNEL, "dummy%d", dummy_index);
+		map->debugfs_name = kasprintf(GFP_KERNEL, "dummy%d",
+						dummy_index);
+		name = map->debugfs_name;
 		dummy_index++;
 	}