*Fix new scaling bug in ML restrat minimum ustar

  There are extra US%T_to_s scaling factors in the expressions for ustar_min
that were recently introduced with dev/gfdl PR mom-ocean#251; these are duplicative of
the scaling factor that is already being applied when the parameter OMEGA is
read in.  The resulting expressions for ustar_min therefore effectively have
units of [Z s T-2 ~> m s-1] when they should have units of [Z T-1 ~> m s-1].
Because ustar_min is a tiny floor on the magnitude of ustar, there is a range of
values of T_RESCALE_POWER that will give the same answers as when it is 0, but
for large enough values the answers will change, perhaps dramatically.  This
small commit removes these extra factors.  Answers will change for some large
values of T_RESCALE_POWER, but they are bitwise identical in the TC testing and
in MOM6-examples based regression tests with modest or negative values.

src/parameterizations/lateral/MOM_mixed_layer_restrat.F90

@@ -309,7 +309,7 @@ subroutine mixedlayer_restrat_general(h, uhtr, vhtr, tv, forces, dt, MLD_in, Var
   g_Rho0 = GV%g_Earth / GV%Rho0
   h_neglect = GV%H_subroundoff
   dz_neglect = GV%H_subroundoff*GV%H_to_Z
-  ustar_min = 2e-4 * CS%omega * US%T_to_S * (GV%Angstrom_Z + dz_neglect)
+  ustar_min = 2e-4 * CS%omega * (GV%Angstrom_Z + dz_neglect)
   if (CS%front_length>0.) then
     res_upscale = .true.
     I_LFront = 1. / CS%front_length
@@ -666,7 +666,7 @@ subroutine mixedlayer_restrat_BML(h, uhtr, vhtr, tv, forces, dt, G, GV, US, CS)
   use_EOS    = associated(tv%eqn_of_state)
   h_neglect  = GV%H_subroundoff
   dz_neglect = GV%H_subroundoff*GV%H_to_Z
-  ustar_min = 2e-4 * CS%omega * US%T_to_S * (GV%Angstrom_Z + dz_neglect)
+  ustar_min = 2e-4 * CS%omega * (GV%Angstrom_Z + dz_neglect)
 
   if (.not.use_EOS) call MOM_error(FATAL, "MOM_mixedlayer_restrat: "// &
          "An equation of state must be used with this module.")
@@ -932,9 +932,8 @@ logical function mixedlayer_restrat_init(Time, G, GV, US, param_file, diag, CS,
              units="nondim", default=1.0)
   endif
   call get_param(param_file, mdl, "OMEGA", CS%omega, &
-       "The rotation rate of the earth.", units="s-1", &
-       default=7.2921e-5, scale=US%T_to_s)
-
+             "The rotation rate of the earth.", &
+             units="s-1", default=7.2921e-5, scale=US%T_to_s)
 
   CS%diag => diag