msm: kgsl: Use recovery data structure to extract valid commands

Use the data set in the recovery structure when extracting
valid commands from the ringbuffer instead of reading
it from the device/memory.

Change-Id: I9cbcc09b1ce95313c2d3cf59fbb649dad2cb9d99
Signed-off-by: Shubhraprakash Das <sadas@codeaurora.org>