lwout_x3d.c warnings

[strk]

lwout_x3d.c: In function ‘asx3d3_line_coords’:
lwout_x3d.c:180: warning: passing argument 1 of ‘lwline_is_closed’ discards qualifiers from pointer target type
liblwgeom.h:1587: note: expected ‘struct LWLINE *’ but argument is of type ‘const struct LWLINE *’
lwout_x3d.c: In function ‘asx3d3_mline_coordindex’:
lwout_x3d.c:194: warning: zero-length gnu_printf format string
lwout_x3d.c: In function ‘asx3d3_multi_buf’:
lwout_x3d.c:431: warning: passing argument 1 of ‘asx3d3_mline_coordindex’ from incompatible pointer type
lwout_x3d.c:186: note: expected ‘const struct LWMLINE *’ but argument is of type ‘const struct LWCOLLECTION *’
lwout_x3d.c:437: warning: passing argument 1 of ‘asx3d3_mpoly_coordindex’ from incompatible pointer type
lwout_x3d.c:233: note: expected ‘const struct LWMPOLY *’ but argument is of type ‘const struct LWCOLLECTION *’
lwout_x3d.c:442: warning: return makes integer from pointer without a cast

[robe]

I think this is a dupe of #999