mcf: Fix using 4th param in weboslayers.py as LOCATION (v4.0.3)

:Release Notes:
Fix downloadrepo and updaterepo functions to work correctly when 4th
parameter is used and bonus allow to use it as dirname for checkout.

:Detailed Notes:
It's useful to checkout e.g.
  git://git.openembedded.org/openembedded-core-contrib
instead of
  git://github.com/openembedded/oe-core.git
but in "oe-core" subdirectory, because other parts of build are
hard-coding "oe-core" path. Remove DIRNAME variable, one variable for
location is enough.

:Testing Performed:
Only build tested.

:QA Notes:
No change to image.

:Issues Addressed:
[ES-451] mcf: Update remote URL when it's changed in weboslayers.py

Open-webOS-DCO-1.0-Signed-off-by: Martin Jansa <martin.jansa@lge.com>
Change-Id: I164bbea8a1a20b9122653efb3f11d1994b24f3f5
Reviewed-on: https://g2g.palm.com/4995
Reviewed-by: DCO Verification
Build: Martin Jansa <Martin.Jansa@lge.com>
Reviewed-by: Martin Jansa <Martin.Jansa@lge.com>
Tested-by: Martin Jansa <Martin.Jansa@lge.com>
Reviewed-by: Build Verification
Reviewed-by: Susan Montooth <susan.montooth@lge.com>