Match function signature in definition with declaration

Match function signature in definition with declaration

GCC11 throws the following warning:
graphviz/lib/pathplan/shortest.c:93:47: warning: argument 2 of type ‘Ppoint_t *’ {aka ‘struct Pxy_t *’} declared as a pointer [-Warray-parameter=]
   93 | int Pshortestpath(Ppoly_t * polyp, Ppoint_t * eps, Ppolyline_t * output)
      |                                    ~~~~~~~~~~~^~~
In file included from graphviz/lib/pathplan/pathutil.h:15,
                 from graphviz/lib/pathplan/shortest.c:16:
graphviz/lib/pathplan/pathplan.h:22:59: note: previously declared as an array ‘Ppoint_t[2]’ {aka ‘struct Pxy_t[2]’}
   22 |     extern int Pshortestpath(Ppoly_t * boundary, Ppoint_t endpoints[2],
      |                                                  ~~~~~~~~~^~~~~~~~~~~~
[2/20] Building C object lib/pathplan/CMakeFiles/pathplan.dir/route.c.o
graphviz/lib/pathplan/route.c:76:29: warning: argument 4 of type ‘Ppoint_t *’ {aka ‘struct Pxy_t *’} declared as a pointer [-Warray-parameter=]
   76 |                  Ppoint_t * evs, Ppolyline_t * output)
      |                  ~~~~~~~~~~~^~~
In file included from graphviz/lib/pathplan/pathutil.h:15,
                 from graphviz/lib/pathplan/route.c:17:
graphviz/lib/pathplan/pathplan.h:28:39: note: previously declared as an array ‘Pvector_t[2]’ {aka ‘struct Pxy_t[2]’}
   28 |                             Pvector_t endpoint_slopes[2],
      |                             ~~~~~~~~~~^~~~~~~~~~~~~~~~~~