The "{forward,back} to %s, correct to nearest" tests were reporting
the time of the transition as %s but, like the jump test, were using
the middle of the gap as the time to set. So compute that mid-time's
string once and use it in all three test names. Also renamed some
local variables to accommodate the new one for this text.
Pick-to: 6.5
Change-Id: Ic6c40c470fc74ae8bcfc0dc9d1596af06318a883
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>