Update models_mesh_picking.c

Hi. It was throwing:
gcc -o models_mesh_picking.exe models_mesh_picking.c -s C:\raylib\raylib\raylib_icon -Iexternal -lraylib -lglfw3 -lopengl32 -lgdi32 -lopenal32 -lwinmm -std=c99 -Wl,-allow-multiple-definition -Wl,--subsystem,windows
Process started >>>
models_mesh_picking.c: In function 'main':
models_mesh_picking.c:92:20: warning: implicit declaration of function 'Vector3Barycenter' [-Wimplicit-function-declaration]
             bary = Vector3Barycenter(nearestHit.position, ta, tb, tc);
                    ^
models_mesh_picking.c:92:18: error: incompatible types when assigning to type 'Vector3 {aka struct Vector3}' from type 'int'
             bary = Vector3Barycenter(nearestHit.position, ta, tb, tc);
                  ^
<<< Process finished. (Exit code 1)

examples/models/models_mesh_picking.c

@@ -89,7 +89,7 @@ int main()
             cursorColor = PURPLE;
             hitObjectName = "Triangle";
 
-            bary = Vector3Barycenter(nearestHit.position, ta, tb, tc);
+            bary = (nearestHit.position, ta, tb, tc);
             hitTriangle = true;
         } 
         else hitTriangle = false;