trace/syscalls: Change ret param in struct syscall_trace_exit to long

Commit ee949a86b3aef15845ea677aa60231008de62672 ("tracing/syscalls:
Use long for syscall ret format and field definitions") changed the
syscall exit return type to long, but forgot to change it in the
struct.

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1259133299-23594-3-git-send-email-tzanussi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/trace/trace.h

@@ -100,7 +100,7 @@ struct syscall_trace_enter {
 struct syscall_trace_exit {
 	struct trace_entry	ent;
 	int			nr;
-	unsigned long		ret;
+	long			ret;
 };
 
 struct kprobe_trace_entry {