[IA64] correct file descriptor reference counting in perfmon (CVE-2006-3741)

Fix a bug in sys_perfmonctl() whereby it was not correctly
decrementing the file descriptor reference count.
Signed-off-by: Stephane Eranian <eranian@hpl.hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

arch/ia64/kernel/perfmon.c

@@ -4937,13 +4937,15 @@ sys_perfmonctl (int fd, int cmd, void __user *arg, int count)
 	if (likely(ctx)) {
 		DPRINT(("context unlocked\n"));
 		UNPROTECT_CTX(ctx, flags);
-		fput(file);
 	}
 
 	/* copy argument back to user, if needed */
 	if (call_made && PFM_CMD_RW_ARG(cmd) && copy_to_user(arg, args_k, base_sz*count)) ret = -EFAULT;
 
 error_args:
+	if (file)
+		fput(file);
+
 	kfree(args_k);
 
 	DPRINT(("cmd=%s ret=%ld\n", PFM_CMD_NAME(cmd), ret));