perf trace: Fix incorrectly parsed hexadecimal value for flags in filter

When parsing flags in filter, the strtoul function uses wrong parsing
condition (tok[1] = 'x'), which can make the flags be corrupted and
treat all numbers start with 0 as hex.

In fact strtoul() will auto test hex format when base == 0 (See
_parse_integer_fixup_radix). So there is no need to test this again.

Remove the unnessesary is_hexa test.

Fixes: 154c978d ("libbeauty: Introduce strarray__strtoul_flags()")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Florian Fischer <florian.fischer@muhq.space>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20220926031440.28275-3-chenzhongjin@huawei.com


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