Output error with variable spin and Methfessel-Paxton smearing

[davidbowler]

When the spin is not fixed (Spin.FixSpin F) then during findFermi_varspin in DiagModule.f90 when using Methfessel-Paxton smearing, a warning message can be written if the number of electrons is more than 10 electrons away from the target which uses the wrong format statement.

https://github.com/OrderN/CONQUEST-release/blob/6bf8f4a8c20fd4fa8f1c7baeb8a6b1f23a6d2408/src/DiagModule.f90#L2726-L2731

This should be easy to fix: it gives an alarming message (e.g. Fermi level is 1547.66031 and then Fermi level is 10.00000 where it is indicating the number of electrons and parameter Diag.NElecLess not the Fermi level!)