Rename local variable k2 to d

Following commit 4792f83f.

Common/read_snapshot.f90

@@ -35,7 +35,7 @@ contains
 
     ! Local:
     integer ishape, ishape_first
-    integer k2 ! date index
+    integer d ! date index
     integer i ! eddy index
     type(eddy) e
 
@@ -52,10 +52,10 @@ contains
     allocate(s%list_vis(s%number_vis_extr))
 
     do ishape = ishape_first, ishape_last(k - d_init + 1)
-       call read_eddy(e, k2, i, hshp, ishape)
+       call read_eddy(e, d, i, hshp, ishape)
 
        ! Check that all the eddies have the same date index:
-       call assert(k2 == k, "read_snapshot: date index")
+       call assert(d == k, "read_snapshot: date index")
 
        s%list_vis(i) = e
     end do