msm: kgsl: Fix invalid pointer reference at a few places

kgsl_allocate_global can fail for global buffer profile_desc. Hence make
sure that an invalid access to the pointer is not made in
set_user_profiling. Similarly allocations for global buffers setstate and
alwayson can also fail. Make sure we don't access an invalid pointer in
adreno_snapshot_global and kgsl_gpuaddr_in_memdesc.

Change-Id: Ia2f314575c5f4357ac8f7a2a72e869e3c648837d
Signed-off-by: Puranam V G Tejaswi <pvgtejas@codeaurora.org>