msm: kgsl: Fix profiler buffer wrapping from running out of space

When the shared buffer wraps around, we lose a little space from the
buffer since logging only works on packet count offsets (deteremined by
how many performance counters per submission). If this continues, then
each time we wrap around we lose a little space from our buffer.
Reset the max buffer size when the processing of the data is done and
the buffer wrapped to avoid decrementing the max size to 0 after several
minutes.

CRs-fixed: 717082
Change-Id: If5367d9cf48c96ca42a1f94fb669090c8ca80538
Signed-off-by: Carter Cooper <ccooper@codeaurora.org>