perf jevents: Append PMU description later

Append the PMU information from "Unit" to the description later. This
avoids a problem when "Unit" appears early in a json event and the
information prepends the description rather than being the expected
suffix.

Update the pmu-events test so that expectations now match the improved
output.

Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ananth Narayan <ananth.narayan@amd.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrew Kilroy <andrew.kilroy@arm.com>
Cc: Caleb Biggers <caleb.biggers@intel.com>
Cc: Felix Fietkau <nbd@nbd.name>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kshipra Bopardikar <kshipra.bopardikar@intel.com>
Cc: Like Xu <likexu@tencent.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nick Forrington <nick.forrington@arm.com>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Perry Taylor <perry.taylor@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qi Liu <liuqi115@huawei.com>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Santosh Shukla <santosh.shukla@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20220511211526.1021908-2-irogers@google.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>