Fix a problem with sys_lseek on x32

* file.c (sys_lseek): Use MIPS-n32 variant also for x32

Signed-off-by: H.J. Lu <hongjiu.lu@intel.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/file.c b/file.c
index 58585f3..5f3b506 100644
--- a/file.c
+++ b/file.c
@@ -501,7 +501,7 @@
 	{ 0,		NULL		},
 };
 
-#if defined(LINUX_MIPSN32)
+#if defined(LINUX_MIPSN32) || defined(X32)
 int
 sys_lseek(struct tcb *tcp)
 {