*: use void * for printing pointers

On higher warning levels, compilers expect %p printf arguments to be
void *.  Since format string / argument warnings can be useful
otherwise, let's get rid of this noise by sprinkling casts to void *
over printf calls.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
diff --git a/isisd/isis_spf.c b/isisd/isis_spf.c
index a4cbba6..28525ce 100644
--- a/isisd/isis_spf.c
+++ b/isisd/isis_spf.c
@@ -1072,8 +1072,8 @@
 	    {
 	      zlog_warn ("ISIS-Spf: No lsp (%p) found from root "
                   "to L%d DR %s on %s (ID %d)",
-		  lsp, level, rawlspid_print (lsp_id), 
-		  circuit->interface->name, circuit->circuit_id);
+                  (void *)lsp, level, rawlspid_print (lsp_id),
+                  circuit->interface->name, circuit->circuit_id);
               continue;
 	    }
 	  isis_spf_process_pseudo_lsp (spftree, lsp,