staging: lustre: lov: copy_to_user uses wrong casting

staging: lustre: lov: copy_to_user uses wrong casting

With certain version of gcc lov_obd.c failes to compile
with the following warning.

In function copy_to_user,
inlined from lov_iocontrol at
lustre/lustre/lov/lov_obd.c:1168:
./arch/x86/include/asm/uaccess.h:735: error: call to
__copy_to_user_overflow declared with attribute warning:
copy_to_user() buffer size is not probably correct

In lov_iocontrol the data was being casted to int instead
of the required unsigned long. This patch changes the cast
to what is needed for copy_to_user.

Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6302
Reviewed-on: http://review.whamcloud.com/14613
Reviewed-by: frank zago <fzago@cray.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>