libpixelflinger: do not use anonymous structs

Avoiding the use of gnu extensions improves code portability

Change-Id: Ie9e94e3ce030f52a22997f8a48de1e6c1c549894
diff --git a/libpixelflinger/scanline.cpp b/libpixelflinger/scanline.cpp
index a5d28b2..9663a2b 100644
--- a/libpixelflinger/scanline.cpp
+++ b/libpixelflinger/scanline.cpp
@@ -1877,7 +1877,7 @@
             struct {
                 int32_t s, sq;
                 int32_t t, tq;
-            };
+            } sqtq;
             struct {
                 int32_t v, q;
             } st[2];
@@ -1916,10 +1916,10 @@
         int32_t t =   tmu.shade.it0 +
                      (tmu.shade.idtdy * ys) + (tmu.shade.idtdx * xs) +
                      ((tmu.shade.idtdx + tmu.shade.idtdy)>>1);
-        tc[i].s  = s;
-        tc[i].t  = t;
-        tc[i].sq = gglMulx(s, q0, iwscale);
-        tc[i].tq = gglMulx(t, q0, iwscale);
+        tc[i].sqtq.s  = s;
+        tc[i].sqtq.t  = t;
+        tc[i].sqtq.sq = gglMulx(s, q0, iwscale);
+        tc[i].sqtq.tq = gglMulx(t, q0, iwscale);
     }
 
     int32_t span = 0;