staging: lustre: libcfs: Fix libcfs_ioctl() prototype.

Fix libcfs_ioctl() prototype according to its definition in
libcfs/module.c.
Signed-off-by: Aleksei Fedotov <lexa@cfotr.com>
Acked-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/include/linux/libcfs/libcfs.h

@@ -106,7 +106,7 @@ int libcfs_deregister_ioctl(struct libcfs_ioctl_handler *hand);
 int libcfs_ioctl_getdata(struct libcfs_ioctl_hdr **hdr_pp,
 			 const struct libcfs_ioctl_hdr __user *uparam);
 int libcfs_ioctl_data_adjust(struct libcfs_ioctl_data *data);
-int libcfs_ioctl(unsigned long cmd, void *arg);
+int libcfs_ioctl(unsigned long cmd, void __user *arg);
 
 /* container_of depends on "likely" which is defined in libcfs_private.h */
 static inline void *__container_of(void *ptr, unsigned long shift)