iproute2: fix 'ip xfrm monitor all' command

iproute2: fix 'ip xfrm monitor all' command

Currently, calling 'ip xfrm monitor all' will
actually invoke the 'all-nsid' command because the
soft-match for 'all-nsid' occurs before the precise
match for 'all'. This patch rearranges the checks
so that the 'all' command, itself an alias for
invoking 'ip xfrm monitor' with no argument, can
be called consistent with the syntax for other ip
commands that accept an 'all'.

Signed-off-by: Nathan Harold <nharold@google.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>