perf daemon: Remove duplicate includes

sys/stat.h has been included at line 23, so remove the
duplicate one at line 27.

linux/string.h has been included at line 7, so remove the
duplicate one at line 9.

time.h has been included at line 14, so remove the
duplicate one at line 28.

Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: kael_w@yeah.net
Link: http://lore.kernel.org/lkml/20210323050139.287461-1-wanjiabing@vivo.com


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