MIPS: 64-bit: Fix o32 lookup_dcookie syscall

An o32 aplication passes a 64-bit value in a pair of registers; a 64-bit
kernel expects a 64-bit argument in a single register.
Signed-off-by: Chen Jie <chenj@lemote.com>
Signed-off-by: Hu Hongbing <huhb@lemote.com>
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/linux32.c

@@ -428,3 +428,9 @@ _sys32_clone(nabi_no_regargs struct pt_regs regs)
 	return do_fork(clone_flags, newsp, &regs, 0,
 	               parent_tidptr, child_tidptr);
 }
+
+asmlinkage long sys32_lookup_dcookie(u32 a0, u32 a1, char __user *buf,
+	size_t len)
+{
+	return sys_lookup_dcookie(merge_64(a0, a1), buf, len);
+}

arch/mips/kernel/scall64-o32.S

@@ -450,7 +450,7 @@ sys_call_table:
 	PTR	sys_io_submit
 	PTR	sys_io_cancel			/* 4245 */
 	PTR	sys_exit_group
-	PTR	sys_lookup_dcookie
+	PTR	sys32_lookup_dcookie
 	PTR	sys_epoll_create
 	PTR	sys_epoll_ctl
 	PTR	sys_epoll_wait			/* 4250 */