perf-record: Check correct pid when forking

When forking the child to be traced, we should check the correct
return value from fork() and not a local variable which is otherwise
unused.

Signed-off-by: Borislav Petkov <bp@alien8.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <20100531211818.GA30175@liondog.tnic>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

tools/perf/builtin-record.c

@@ -503,7 +503,6 @@ static int __cmd_record(int argc, const char **argv)
 {
 	int i, counter;
 	struct stat st;
-	pid_t pid = 0;
 	int flags;
 	int err;
 	unsigned long waking = 0;
@@ -572,7 +571,7 @@ static int __cmd_record(int argc, const char **argv)
 
 	if (forks) {
 		child_pid = fork();
-		if (pid < 0) {
+		if (child_pid < 0) {
 			perror("failed to fork");
 			exit(-1);
 		}