Small change WaveTp logic

Author: RBergua

modules/seastate/src/SeaState_Input.f90

@@ -701,7 +701,7 @@ subroutine SeaStateInput_ProcessInitData( InitInp, p, InputFileData, ErrStat, Er
         InputFileData%WaveMod == WaveMod_RegularUsrPh .OR. &
         InputFileData%WaveMod == WaveMod_JONSWAP ) then
 
-      if ( InputFileData%Waves%WaveTp <= 0.0 )  then
+      if ( InputFileData%Waves%WaveTp <= 0.0_SiKi )  then
          call SetErrStat( ErrID_Fatal,'WaveTp must be greater than zero.',ErrStat,ErrMsg,RoutineName)
          return
       end if