ANDROID: sdcardfs: Use to kstrout

Switch from deprecated simple_strtoul to kstrout

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Bug: 35331000
Change-Id: If18bd133b4d2877f71e58b58fc31371ff6613ed5
diff --git a/fs/sdcardfs/derived_perm.c b/fs/sdcardfs/derived_perm.c
index 411a9a9..14747a8 100644
--- a/fs/sdcardfs/derived_perm.c
+++ b/fs/sdcardfs/derived_perm.c
@@ -60,6 +60,8 @@ void get_derived_permission_new(struct dentry *parent, struct dentry *dentry,
 	struct sdcardfs_inode_info *info = SDCARDFS_I(d_inode(dentry));
 	struct sdcardfs_inode_info *parent_info = SDCARDFS_I(d_inode(parent));
 	appid_t appid;
+	unsigned long user_num;
+	int err;
 	struct qstr q_Android = QSTR_LITERAL("Android");
 	struct qstr q_data = QSTR_LITERAL("data");
 	struct qstr q_obb = QSTR_LITERAL("obb");
@@ -88,7 +90,11 @@ void get_derived_permission_new(struct dentry *parent, struct dentry *dentry,
 	case PERM_PRE_ROOT:
 		/* Legacy internal layout places users at top level */
 		info->perm = PERM_ROOT;
-		info->userid = simple_strtoul(name->name, NULL, 10);
+		err = kstrtoul(name->name, 10, &user_num);
+		if (err)
+			info->userid = 0;
+		else
+			info->userid = user_num;
 		set_top(info, &info->vfs_inode);
 		break;
 	case PERM_ROOT: