perf tools: Refactor the code to strip command name with {l,r}trim()

After reading command name from /proc/<pid>/status, use ltrim() and
rtrim() to strip command name, not using just while loop, isspace() and
etc.

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Acked-by: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1491575061-704-6-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/event.c

@@ -106,7 +106,7 @@ static int perf_event__get_comm_ids(pid_t pid, char *comm, size_t len,
 	int fd;
 	size_t size = 0;
 	ssize_t n;
-	char *nl, *name, *tgids, *ppids;
+	char *name, *tgids, *ppids;
 
 	*tgid = -1;
 	*ppid = -1;
@@ -134,14 +134,7 @@ static int perf_event__get_comm_ids(pid_t pid, char *comm, size_t len,
 
 	if (name) {
 		name += 5;  /* strlen("Name:") */
-
-		while (*name && isspace(*name))
-			++name;
-
-		nl = strchr(name, '\n');
-		if (nl)
-			*nl = '\0';
-
+		name = rtrim(ltrim(name));
 		size = strlen(name);
 		if (size >= len)
 			size = len - 1;