kasan: mm: Remove redundant kasan page alloc and free calls

Remove redundant calls of kasan_alloc_pages()
and kasan_free_pages(). Commit 63d16fa3
("Merge tag 'lsk-v3.18-16.04-android' into 'msm-3.18'")
brought in redundant calls and leading device boot up
failures. So remove the redundant kasan_alloc_pages() and
kasan_free_pages() calls.

Change-Id: I383759466617777f31db44e53cf78cacf7c612b0
Signed-off-by: Mohammed Khajapasha <mkhaja@codeaurora.org>