GPU: consistenly use mipmap on/off in all draw modes.

This is important for good texture paint performance.

source/blender/gpu/intern/gpu_draw.c

@@ -288,8 +288,7 @@ GPUTexture *GPU_texture_from_blender(Image *ima,
                                      ImageUser *iuser,
                                      int textarget,
                                      bool is_data,
-                                     double UNUSED(time),
-                                     int mipmap)
+                                     double UNUSED(time))
 {
 	if (ima == NULL) {
 		return NULL;
@@ -361,6 +360,8 @@ GPUTexture *GPU_texture_from_blender(Image *ima,
 		}
 	}
 
+	const bool mipmap = GPU_get_mipmap();
+
 #ifdef WITH_DDS
 	if (ibuf->ftype == IMB_FTYPE_DDS)
 		GPU_create_gl_tex_compressed(&bindcode, rect, rectw, recth, textarget, mipmap, ima, ibuf);