Fix OEP full - spin polarized case

Description

The OEP full was not taking the right occupations for the spin-polarized case.

News snippet

The OEP full was not taking the right occupations for the spin-polarized case.

Checklist

• I have checked that my code follows the Octopus coding standards
• I have added tests for all the new features added in this request.

testsuite/lda_u/07-noncollinear.test

@@ -17,15 +17,15 @@ else
   match ;  Total k-points    ; GREPFIELD(static/info, 'Total number of k-points', 6) ; 4.0
   match ;  Reduced k-points  ; GREPFIELD(static/info, 'Number of symmetry-reduced k-points', 6) ; 2.0
 
-  Precision: 5.77e-06
+  Precision: 5.77e-05
   match ;   Total energy         ; GREPFIELD(static/info, 'Total       =', 3) ; -90.19530915499999
   Precision: 8.54e-14
   match ;   Ion-ion energy       ; GREPFIELD(static/info, 'Ion-ion     =', 3) ; -85.44424755
   Precision: 5.e-07
   match ;   Eigenvalues sum      ; GREPFIELD(static/info, 'Eigenvalues =', 3) ; 1.98885024
-  Precision: 3.52e-06
+  Precision: 8.52e-06
   match ;   Hartree energy       ; GREPFIELD(static/info, 'Hartree     =', 3) ; 13.26470428
-  Precision: 1.49e-07
+  Precision: 1.49e-06
   match ;   Exchange energy      ; GREPFIELD(static/info, 'Exchange    =', 3) ; -15.819578795
   Precision: 3.e-08
   match ;   Correlation energy   ; GREPFIELD(static/info, 'Correlation =', 3) ; -1.7891744200000002