SGP/EBBR - EBBR E7 Soil Moistures #2 and #4 Incorrect

Soil moisture #2 and #4 were negative, often large negative, during very
dry soil conditions, causing several other quantities to also be incorrect. 

The affected data are:

15 minute: r_sm2, r_sm4
30 minute: sm2, sm4, c_shf2, c_shf4, cs2, cs4, ces2, ces4, g2, g4,
           ave_shf, h, e

• Soil moisture 4 (resistance)(soil_moisture_4_r)
• Soil moisture 2 (resistance)(soil_moisture_2_r)

• Surface latent heat flux(latent_heat_flux)
• Soil moisture 4, gravimetric(soil_moisture_4)
• Soil moisture 2, gravimetric(soil_moisture_2)
• Surface soil heat flux 4(surface_soil_heat_flux_4)
• Surface soil heat flux 2(surface_soil_heat_flux_2)
• Soil heat flow 2, corrected for soil moisture(corr_soil_heat_flow_2)
• Soil heat capacity 2(soil_heat_capacity_2)
• Soil heat flow 4, corrected for soil moisture(corr_soil_heat_flow_4)
• Surface soil heat flux, average of fluxes 1-5(surface_soil_heat_flux_avg)
• Soil heat capacity 4(soil_heat_capacity_4)
• Change in energy storage 4, 0-5 cm soil layer(energy_storage_change_4)
• Surface sensible heat flux(sensible_heat_flux)
• Change in energy storage 2, 0-5 cm soil layer(energy_storage_change_2)