Simplify meaning of `n_max_cont`

`n_max_cont` is just the maximum number of contours in `cont_list`,
and `n_cont` is the actual number.

Inst_eddies/set_all_outerm.f90

@@ -64,7 +64,7 @@ contains
 
     integer, parameter:: n_max_cont = 31
 
-    type(ssh_contour) cont_list(n_max_cont + 1)
+    type(ssh_contour) cont_list(n_max_cont)
     ! Contour list. The outermost contour is element n_cont. The
     ! contours are in monotonic order of ssh.