[RFC 3/4] cyclictest: move tracemark_fd handling to its own function

[Luiz Capitulino <lcapitulino@redhat.com>]

A function added by the next commit will want to call
this code too.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 src/cyclictest/cyclictest.c | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c
index f543c34..e35088b 100644
--- a/src/cyclictest/cyclictest.c
+++ b/src/cyclictest/cyclictest.c
@@ -497,6 +497,19 @@ static void debugfs_prepare(void)
 		fileprefix = procfileprefix;
 }
 
+static void open_tracemark_fd(void)
+{
+	char path[MAX_PATH];
+
+	if (tracemark_fd >= 0)
+		return;
+
+	sprintf(path, "%s/%s", fileprefix, "trace_marker");
+	tracemark_fd = open(path, O_WRONLY);
+	if (tracemark_fd < 0)
+		warn("unable to open trace_marker file: %s\n", path);
+}
+
 static void setup_tracer(void)
 {
 	if (!tracelimit || notrace)
@@ -612,14 +625,7 @@ static void setup_tracer(void)
 				fatal("unable to open %s for tracing", path);
 		}
 
-		/* open the tracemark file descriptor */
-		if (tracemark_fd == -1) {
-			char path[MAX_PATH];
-			strcat(strcpy(path, fileprefix), "trace_marker");
-			if ((tracemark_fd = open(path, O_WRONLY)) == -1)
-				warn("unable to open trace_marker file: %s\n", path);
-		}