ANDROID: sdcardfs: Use spin_lock_nested

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Bug: 36007653
Change-Id: I805d5afec797669679853fb2bb993ee38e6276e4
diff --git a/fs/sdcardfs/dentry.c b/fs/sdcardfs/dentry.c
index f22de8a..d1eff45 100644
--- a/fs/sdcardfs/dentry.c
+++ b/fs/sdcardfs/dentry.c
@@ -76,10 +76,10 @@
 
 	if (dentry < lower_dentry) {
 		spin_lock(&dentry->d_lock);
-		spin_lock(&lower_dentry->d_lock);
+		spin_lock_nested(&lower_dentry->d_lock, DENTRY_D_LOCK_NESTED);
 	} else {
 		spin_lock(&lower_dentry->d_lock);
-		spin_lock(&dentry->d_lock);
+		spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
 	}
 
 	if (dentry->d_name.len != lower_dentry->d_name.len) {