return tuple points from GeoInterface methods

Author: rafaqz

src/geo_interface.jl

@@ -67,17 +67,14 @@ end
 
 function _get_tuple_point(geom, seq, (x, y, z), i, context = get_global_context(), hasz=hasZ(geom, context))
     if hasz
-        GC.@preserve x y z begin
-            GEOSCoordSeq_getXYZ_r(context, seq, i - UInt32(1), x, y, z)
-        end
+        GEOSCoordSeq_getXYZ_r(context, seq, i - UInt32(1), x, y, z)
         return x[], y[], Z[]
     else
-        GC.@preserve x y begin
-            GEOSCoordSeq_getXY_r(context, seq, i - UInt32(1), x, y)
-        end
+        GEOSCoordSeq_getXY_r(context, seq, i - UInt32(1), x, y)
         return x[], y[]
     end
 end
+
 GeoInterface.getgeom(t::AbstractPointTrait, geom::PreparedGeometry) = nothing
 function GeoInterface.getgeom(::PolygonTrait, geom::Polygon, i::Int)
     if i == 1