perf tests record: No need to test an array against NULL

perf tests record: No need to test an array against NULL

It will always evaluate to 'true', as clang warns:

    CC       /tmp/build/perf/tests/perf-record.o
    CC       /tmp/build/perf/tests/evsel-roundtrip-name.o
  tests/perf-record.c:69:24: error: comparison of array 'argv' equal to a null pointer is always false [-Werror,-Wtautological-pointer-compare]
          if (evlist == NULL || argv == NULL) {
                                ^~~~    ~~~~
  1 error generated.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-o4977g6p9b3peak9ct6ef48q@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>