perf test: Do not be case sensitive when searching for matching tests

Before:

  # perf test llvm
  # perf test LLVM
  35: Test LLVM searching and compiling                        : Ok
  #

After

  # perf test llvm
  35: Test LLVM searching and compiling                        : Ok
  #

Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

tools/perf/tests/builtin-test.c

@@ -196,7 +196,7 @@ static bool perf_test__matches(struct test *test, int curr, int argc, const char
 			continue;
 		}
 
-		if (strstr(test->desc, argv[i]))
+		if (strcasestr(test->desc, argv[i]))
 			return true;
 	}