webadmin: Fix brick advanced details close button

Brick advanced details popup's close button was
not working, this is fixed now.

Change-Id: Id946d396e22822fa9b0eb094ec36ba73b54d0220
Bug-Url: https://bugzilla.redhat.com/919402
Signed-off-by: Kanagaraj M <kmayilsa@redhat.com>