packagegroup-core-tools-profile: Fix parsing error

:Release Notes:
Fix bug in previous commit where the recipe would fail to parse if
WEBOS_LTTNG_ENABLED was undefined.

:Detailed Notes:

:Testing Performed:
Confirmed that "bitbake -e packagegroup-core-tools-profile" succeeded
with WEBOS_LTTNG_ENABLED undefined.

:QA Notes:

:Issues Addressed:
[GF-58032] LTTng dynamic libraries appear in the production image

Open-webOS-DCO-1.0-Signed-off-by: Herb Kuta <herb.kuta@lge.com>

Change-Id: I6b9b10c73364db66843d1822a978c636336ff275
Reviewed-on: https://g2g.palm.com/4426
Reviewed-by: DCO Verification
Build: Herb Kuta <herb.kuta@lge.com>
Reviewed-by: Herb Kuta <herb.kuta@lge.com>
Tested-by: Herb Kuta <herb.kuta@lge.com>
Reviewed-by: Martin Jansa <Martin.Jansa@lge.com>
Reviewed-by: Build Verification
Reviewed-by: Susan Montooth <susan.montooth@lge.com>