Github #226 Use correct paths returned by FindBoost.cmake
Github #226 Use correct paths returned by FindBoost.cmake

According to the documentation in FindBoost.cmake these
are the correct output variables.

Change-Id: If56874aaafe1577888f73719f0a493088d1ac531
Signed-off-by: Matthew Bentham <286076deec2404ae356dd8bc92f2f71e81044bd4@arm.com>

ARM-software/armnn,ARM-software/armnn,ARM-software/armnn