cifs: handle -EINTR in cifs_setattr

RHBZ: 1848178

Some calls that set attributes, like utimensat(), are not supposed to return
-EINTR and thus do not have handlers for this in glibc which causes us
to leak -EINTR to the applications which are also unprepared to handle it.

For example tar will break if utimensat() return -EINTR and abort unpacking
the archive. Other applications may break too.

To handle this we add checks, and retry, for -EINTR in cifs_setattr()

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>