LU-5690 mount: fix lmd_parse() to handle commas in expr_list

LU-5690 mount: fix lmd_parse() to handle commas in expr_list

The lmd_parse() function parses mount options with comma as
delimiter without considering commas in expr_list as follows
is a valid LNET nid range syntax:

<expr_list>  :== '[' <range_expr> [ ',' <range_expr>] ']'

This patch fixes the above issue by using cfs_parse_nidlist()
to parse nid range list instead of using class_parse_nid_quiet()
to parse only one nid.

Signed-off-by: Jian Yu <jian.yu@intel.com>
Change-Id: I8ba6ee6eb31b4bb078a83d9db213cfca27b0fe66
Reviewed-on: http://review.whamcloud.com/17036
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Niu Yawei <yawei.niu@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>