msm: kgsl: Fix buffer overflow while capturing memory entries

We calculate the number of memory entries of a process first
to make sure we have enough memory. When saving the entries,
we use the ID of the entry as an array index. This can result
into array out of bound access as ID can be greater than
the number of memory entries calculated earlier.
Fix this by using the right array index.

Change-Id: I915e565330c21a2604354a05592ae15d62991617
Signed-off-by: Rakesh Naidu Bhaviripudi <quic_rakeshb@quicinc.com>
Signed-off-by: Hemasri Yallanki <quic_hyallank@quicinc.com>