[CIFS] use simple_prepare_write to zero page data
[CIFS] use simple_prepare_write to zero page data

It's common for file systems to need to zero data on either side of a
write, if a page is not Uptodate during prepare_write.  It just so happens
that simple_prepare_write() in libfs.c does exactly that, so we can avoid
duplication and just call that function to zero page data.

Signed-off-by: Nate Diller <6fc6a4dc9f845e43b5470cb34a6cdd3bd24a7b14@gmail.com>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Steve French <d47560e3bac353b8d509d093b1d727868ac7ddf3@us.ibm.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas