HYD-7140 Remove extraneous bracket
HYD-7140 Remove extraneous bracket

An extraneous bracket was found during the review of this patch for
b4_0. A suggestion for more idiomatic Python was also made.

Implement both of these.

 - update update_chroma-externals.py to remove the extraneous bracket
   and to make an expression more idiomatic

Signed-off-by: Brian J. Murrell <2a8f564cbb80211e19c0a14fed38a451599c042f@intel.com>
Change-Id: Id9c5812bfc0343f8fd780fa272c6d4a41804b33c
Reviewed-on: https://review.whamcloud.com/25908
Reviewed-by: Tom Nabarro <27c585386b86ec0acfeeb448326cb9c60162db51@intel.com>
Tested-by: Jenkins
Tested-by: Chroma Test User
Reviewed-by: Kelsey Prantis <891d505c4b8f252568785ec2b0d34b82fde8f616@intel.com>

intel-hpdd/intel-manager-for-lustre,intel-hpdd/intel-manager-for-lustre,intel-hpdd/intel-manager-for-lustre