sched/fair: always use task_fits_max check

task_fits_max calls task_fits_capacity if the CPU is not the
max capacity CPU. Instead of using both the APIs stick to single
API.

Change-Id: Iaa6ddfc352dfa954c9d3a0bb2ed1ad034bec85cf
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>