nfs: Fix truncated client owner id without proto type

The length of "Linux NFSv4.0 " is 14, not 10.

Without this patch, I get a truncated client owner id as,
"Linux NFSv4.0 ::1/::1"

With this patch,
"Linux NFSv4.0 ::1/::1 tcp"

Fixes: a3192688 ("nfs: make nfs4_init_nonuniform_client_string use a dynamically allocated buffer")
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>