perf record: Put new line after target override warning

perf record: Put new line after target override warning

There's no new-line after target-override warning, now:

  $ perf record -a --per-thread
  Warning:
  SYSTEM/CPU switch overriding PER-THREAD^C[ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.705 MB perf.data (2939 samples) ]

with patch:

  $ perf record -a --per-thread
  Warning:
  SYSTEM/CPU switch overriding PER-THREAD
  ^C[ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.705 MB perf.data (2939 samples) ]

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: 16ad2ffb822c ("perf tools: Introduce perf_target__strerror()")
Link: http://lkml.kernel.org/r/20180206181813.10943-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>