data size greater than 8192. Since soreserve(so, 256*1024, 256*1024)
would always fail for the default value of sb_max, modify clnt_dg.c
so that it uses the calculated values and checks for an error return
from soreserve(). Also, add a check for error return from soreserve()
to clnt_vc.c and change __rpc_get_t_size() to use sb_max_adj instead of
the bogus maxsize == 256*1024.
PR: kern/150910
Reviewed by: jhb
MFC after: 2 weeks
8c097aa69e