msm: kgsl: Increment the array size of IB to dump

The array holding list of IB's to dump in snapshot was
not incremented as a result of which IB's were missing in
snapshot.

Change-Id: Idbca6eebf817c9456f6d52aa3c2ea509e732e119
CRs-Fixed: 596932
Signed-off-by: Shubhraprakash Das <sadas@codeaurora.org>