staging: lustre: Replace 'uint32_t' with 'u32' and 'uint64_t' with 'u64'

There are two reasons for replacing 'uint32_t' with 'u32'
and 'uint64_t' with 'u64':

1) As Linus Torvalds have said we should use kernel types:
http://lkml.iu.edu/hypermail//linux/kernel/1506.0/00160.html



2) There are only few places in the lustre codebase that use such types.
In the most cases it uses 'u32' and 'u64'.

Signed-off-by: Roman Storozhenko <romeusmeister@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>