Follow up to the offset scale fix for texture painting: texture mask had

the same issue.

source/blender/blenkernel/intern/brush.c

@@ -684,11 +684,8 @@ float BKE_brush_sample_masktex(const Scene *scene, Brush *br,
 		x /= (br->mask_stencil_dimension[0]);
 		y /= (br->mask_stencil_dimension[1]);
 
-		x *= mtex->size[0];
-		y *= mtex->size[1];
-
-		co[0] = x + mtex->ofs[0];
-		co[1] = y + mtex->ofs[1];
+		co[0] = x;
+		co[1] = y;
 		co[2] = 0.0f;
 
 		externtex(mtex, co, &intensity,
@@ -744,11 +741,8 @@ float BKE_brush_sample_masktex(const Scene *scene, Brush *br,
 			y = flen * sinf(angle);
 		}
 
-		x *= mtex->size[0];
-		y *= mtex->size[1];
-
-		co[0] = x + mtex->ofs[0];
-		co[1] = y + mtex->ofs[1];
+		co[0] = x;
+		co[1] = y;
 		co[2] = 0.0f;
 
 		externtex(mtex, co, &intensity,