regmap: Fix double unlock in the maple cache

Doing the dance to drop the maple tree's internal spinlock means we need
multiple exit paths in our error handling.

Reported-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230403-regmap-maple-unlock-v1-1-89998991b16c@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: broonie

drivers/base/regmap/regcache-maple.c

@@ -137,7 +137,7 @@ static int regcache_maple_drop(struct regmap *map, unsigned int min,
 					GFP_KERNEL);
 			if (!lower) {
 				ret = -ENOMEM;
-				goto out;
+				goto out_unlocked;
 			}
 		}
 
@@ -151,7 +151,7 @@ static int regcache_maple_drop(struct regmap *map, unsigned int min,
 					GFP_KERNEL);
 			if (!upper) {
 				ret = -ENOMEM;
-				goto out;
+				goto out_unlocked;
 			}
 		}
 
@@ -179,6 +179,7 @@ static int regcache_maple_drop(struct regmap *map, unsigned int min,
 
 out:
 	mas_unlock(&mas);
+out_unlocked:
 	kfree(lower);
 	kfree(upper);