LU-14651 build: fix build for el7.9 kernels

LU-14651 build: fix build for el7.9 kernels

Handle extra setattr_prepare() argument added in Linux 5.12 kernels
when building on older kernels.

Lustre-change: https://review.whamcloud.com/53503
Lustre-commit: 7815835d21a5c0b6dbc58d9bc9dd823d4952f86f

HPE-bug-id: LUS-12059
Signed-off-by: Andrew Perepechko <andrew.perepechko@hpe.com>
Change-Id: Ie7fd1c4d51b7a9b086cfca0db941321cbcce7057
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/53504
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Sebastien Buisson <sbuisson@ddn.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Sebastien Buisson <sbuisson@ddn.com>
Tested-by: James Simmons <jsimmons@infradead.org>
Tested-by: Maloo <maloo@whamcloud.com>