staging: lustre: mdc: fixup MDS_SWAP_LAYOUTS ELC handling

In mdc_ioc_swap_layouts() cancel *any* unused locks with LAYOUT or
XATTR IBITS set on the two files. (This matches the locks acquired in
mdt_swap_layouts(). Previously only locks that conflicted with a CR
LAYOUT lock were cancelled.)

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-4320
Reviewed-on: http://review.whamcloud.com/9329


Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Faccini Bruno <bruno.faccini@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>