vfs: extend vfs_removexattr locking
This patch takes the i_mutex lock before security_inode_removexattr(),
instead of after, in preparation of calling ima_inode_removexattr().
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@nokia.com>