ss: fix grammar, articles, and phrasing in man page

This patch addresses grammatical errors, awkward phrasing, missing
articles, and singular/plural agreement issues throughout the ss
man page documentation.

Main corrections:

Grammar and agreement (10 instances):
  - Fix singular/plural: "connection" -> "connections"
  - Fix "five kind" -> "five kinds"
  - Fix "packet" -> "packets" (7 instances throughout memory descriptions)
  - Fix "the retransmission occurred" -> "retransmissions have occurred"
  - Fix "process using socket" -> "processes using sockets"
  - Fix "thread using socket" -> "threads using sockets"
  - Fix "socket option" -> "socket options"

Article corrections:
  - Fix "an uuid" -> "a uuid" (use "a" before consonant sounds)
  - Fix "construct arbitrary set" -> "construct an arbitrary set"
  - Fix "these information" -> "this information" (uncountable noun)
  - Add "instead of human-readable values" (complete phrase)

Awkward phrasing (4 instances):
  - Fix "how long time the timer will expire" -> "how long until the timer will expire"
  - Fix "how long time since" -> "how long it has been since" (3 instances for lastsnd, lastrcv, lastack)

Additional grammar fixes:
  - Add relative pronoun: "memory can be allocated" -> "memory that can be allocated" (2 instances)
  - Fix conditional: "If need memory" -> "If memory is needed"
  - Fix gerund: "before allocate" -> "before allocating"
  - Fix sentence fragment: "Following normal arithmetic rules." -> "following normal arithmetic rules"
  - Add missing period to back_log description

Formatting:
  - Remove duplicate .TP markup between --tipc and --vsock options

No functional changes. All technical content remains accurate.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David Ahern <dsahern@kernel.org>