dsos__add would add at the end of the dso array possibly requiring a
later find to re-sort the array. Patterns of find then add were
becoming O(n*log n) due to the sorts. Change the add routine to be
O(n) rather than O(1) but to maintain the sorted-ness of the dsos
array so that later finds don't need the O(n*log n) sort.

Fixes: 3f4ac23a ("perf dsos: Switch backing storage to array from rbtree/list")
Reported-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Steinar Gunderson <sesse@google.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Matt Fleming <matt@readmodwrite.com>
Link: https://lore.kernel.org/r/20240703172117.810918-3-irogers@google.comSigned-off-by: Namhyung Kim <namhyung@kernel.org>