LU-4612 lvfs: correct call to pop_ctxt

LU-4612 lvfs: correct call to pop_ctxt

Earlier commit 3e7573cc14a331f01150814495e2345793e22f06 that converted
a call of osd_pop_ctxt() to pop_ctxt() ignored the fact the argument
order of these routines were different. This led to panics.

This patch fixes the pop_ctxt() call by putting the arguments
in the correct order.

Signed-off-by: Bob Glossman <bob.glossman@intel.com>
Change-Id: I352250fe3ed91cb8a23a5b8e88b944dc8309b481
Reviewed-on: http://review.whamcloud.com/9224
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Minh Diep <minh.diep@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>