xfs: Hoist xfs_attr_leaf_addname

xfs: Hoist xfs_attr_leaf_addname

Source kernel commit: 83c6e70789ff371c4eebc54f2c8d979305a1bae8

This patch hoists xfs_attr_leaf_addname into the calling function.  The
goal being to get all the code that will require state management into
the same scope. This isn't particularly aesthetic right away, but it is a
preliminary step to merging in the state machine code.

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>