silence some cython warnings

kwant/graph/c_slicer.pxd

@@ -11,7 +11,8 @@ from defs cimport gint
 cdef extern from "c_slicer/slicer.h":
     struct Slicing:
         int nslices
-        int *slice_ptr, *slices
+        int *slice_ptr
+        int *slices
 
     Slicing *slice(gint, gint *, gint *, gint, gint *,
                    gint, gint *)

kwant/graph/core.pyx

@@ -202,8 +202,10 @@ cdef class Graph:
                                                   self.num_pp_edges,
                                                   self.num_pn_edges,
                                                   self.num_np_edges)
-        cdef gint *hbuf = result.heads_idxs + 1, *heads = result.heads
-        cdef gint *tbuf = result.tails_idxs + 1, *tails = result.tails
+        cdef gint *hbuf = result.heads_idxs + 1
+        cdef gint *heads = result.heads
+        cdef gint *tbuf = result.tails_idxs + 1
+        cdef gint *tails = result.tails
         cdef gint *edge_ids = result.edge_ids
         cdef gint edge_id = 0, num_edges     # = 0 is there to silence warning.
         cdef Edge *edge

kwant/linalg/cmumps.pxd

@@ -45,8 +45,10 @@ cdef extern from "zmumps_c.h":
         MUMPS_INT nrhs, lrhs
         ZMUMPS_COMPLEX *rhs
 
-        MUMPS_INT info[40], infog[40]
-        ZMUMPS_REAL rinfo[40], rinfog[40]
+        MUMPS_INT info[40]
+        MUMPS_INT infog[40]
+        ZMUMPS_REAL rinfo[40]
+        ZMUMPS_REAL rinfog[40]
 
         MUMPS_INT nz_rhs
         ZMUMPS_COMPLEX *rhs_sparse