api: fix inversion of barrier marker in elog

api: fix inversion of barrier marker in elog

Currently, the barrier marker for an API message is shown inverted in
the event log. Unsafe API messages are marked as "mp-safe" while safe
ones are marked as "barrier":

  1.332140489: api-msg: sw_interface_dump
  1.332218564: api-msg-done(barrier): sw_interface_dump
  1.332222732: api-msg: control_ping
  1.332241081: api-msg-done(barrier): control_ping
  1.334262103: api-msg: sw_interface_set_flags
  1.334365558: api-msg-done(mp-safe): sw_interface_set_flags

With this fix:

  1.369092258: api-msg: sw_interface_dump
  1.369123551: api-msg-done(mp-safe): sw_interface_dump
  1.369125154: api-msg: control_ping
  1.369132839: api-msg-done(mp-safe): control_ping
  1.370686609: api-msg: sw_interface_set_flags
  1.370735169: api-msg-done(barrier): sw_interface_set_flags

Type: fix
Change-Id: Ib892a83cf801da5fea722eebffd220fabfaa1537
Signed-off-by: Alexander Chernavin <[email protected]>