sched/hmp: Fix memory leak when task fork fails

The scheduler allocates memory for the task load structures during
fork. It then relies to sched_exit() to be called to free that memory.
However, if the fork itself fails at any point after the allocation,
the memory is left unclaimed forever. Fix this memory leak by freeing
the allocated memory under error conditions.

Change-Id: I14a8290c9fcc4174ec80560e9f9d7bcdb119761f
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>