Ensure 'help set/show print inferior-events' shows the example events.

Ensure 'help set/show print inferior-events' shows the example events.

Without this patch, the help stops after  'e.g.' :
  (gdb) apropos \(inferior\|thread\) event
  set print inferior-events -- Set printing of inferior events (e.g.
  set print thread-events -- Set printing of thread events (such as thread start and exit)
  show print inferior-events -- Show printing of inferior events (e.g.
  show print thread-events -- Show printing of thread events (such as thread start and exit)

Using the same notation as for the thread evenets (i.e. 'such as') gives:
 (gdb) apropos \(inferior\|thread\) event
 set print inferior-events -- Set printing of inferior events (such as inferior start and exit)
 set print thread-events -- Set printing of thread events (such as thread start and exit)
 show print inferior-events -- Show printing of inferior events (such as inferior start and exit)
 show print thread-events -- Show printing of thread events (such as thread start and exit)