perf script: Fix missing '+' indicator when branch counter reaches upper limit

perf script: Fix missing '+' indicator when branch counter reaches upper limit

When displaying branch counter (br_cntr) information, a "+" suffix
represents that event occurrences may have been lost due to branch
counter saturation. However, this indicator was missing in perf script.
Add it back.

Before:

 # Branch counter abbr list:
 # cpu_core/event=0xc4,umask=0x20/ppp = A
 # cpu_core/instructions/ = B
 # cpu_core/MEM_INST_RETIRED.ALL_LOADS/ = C
 # cpu_core/MEM_LOAD_RETIRED.L2_MISS/ = D
 # '-' No event occurs
 # '+' Event occurrences may be lost due to branch counter saturated
...
        datasym+190:
        00005567f9951676        jz 0x5567f995162dr_cntr: BBBC   # PRED 1 cycles [1]
...
After:
...
        datasym+190:
        00005567f9951676        jz 0x5567f995162dr_cntr: BBB+C  # PRED 1 cycles [1]
...

Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Thomas Falcon <thomas.falcon@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>