perf record: Fix typo in pid_synthesize_comm_event

We were using 'fd' locally, but there was a global 'fd' too, so
when converting from open to fopen the test made against fd
should be made against 'fp', but since we have that global
it didnt get discovered ...
Reported-by: NUlrich Drepper <drepper@redhat.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20090814182632.GF3490@ghostprotocols.net>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

tools/perf/builtin-record.c

@@ -219,7 +219,7 @@ static pid_t pid_synthesize_comm_event(pid_t pid, int full)
 	snprintf(filename, sizeof(filename), "/proc/%d/status", pid);
 
 	fp = fopen(filename, "r");
-	if (fd == NULL) {
+	if (fp == NULL) {
 		/*
 		 * We raced with a task exiting - just return:
 		 */