LU-6142 tests: Fix style issues for munlink.c

LU-6142 tests: Fix style issues for munlink.c

This patch fixes issues reported by checkpatch
for file lustre/tests/munlink.c

Test-Parameters: trivial
Signed-off-by: Arshad Hussain <arshad.super@gmail.com>
Change-Id: I1722de906c529045fc9a2c8edc877d695840677d
Reviewed-on: https://review.whamcloud.com/35912
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Shaun Tancheff <stancheff@cray.com>
Reviewed-by: Petros Koutoupis <pkoutoupis@cray.com>
Reviewed-by: Ben Evans <bevans@cray.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>