Bitwise to logical & in rdopt ext tx prune function

Making this change in case the future implementation changes and the
compairson is no longer between single bits.

Change-Id: I94f474ce7d82febfa23cec65cbe1b9d240b42e02
diff --git a/av1/encoder/rdopt.c b/av1/encoder/rdopt.c
index d4a089a..3a37fd9 100644
--- a/av1/encoder/rdopt.c
+++ b/av1/encoder/rdopt.c
@@ -707,17 +707,17 @@
   switch (cpi->sf.tx_type_search.prune_mode) {
     case NO_PRUNE: return 0; break;
     case PRUNE_ONE:
-      if ((tx_set >= 0) & !(tx_set_1D[FLIPADST_1D] & tx_set_1D[ADST_1D]))
+      if ((tx_set >= 0) && !(tx_set_1D[FLIPADST_1D] & tx_set_1D[ADST_1D]))
         return 0;
       return prune_one_for_sby(cpi, bsize, x, xd);
       break;
 #if CONFIG_EXT_TX
     case PRUNE_TWO:
-      if ((tx_set >= 0) & !(tx_set_1D[FLIPADST_1D] & tx_set_1D[ADST_1D])) {
+      if ((tx_set >= 0) && !(tx_set_1D[FLIPADST_1D] & tx_set_1D[ADST_1D])) {
         if (!(tx_set_1D[DCT_1D] & tx_set_1D[IDTX_1D])) return 0;
         return prune_two_for_sby(cpi, bsize, x, xd, 0, 1);
       }
-      if ((tx_set >= 0) & !(tx_set_1D[DCT_1D] & tx_set_1D[IDTX_1D]))
+      if ((tx_set >= 0) && !(tx_set_1D[DCT_1D] & tx_set_1D[IDTX_1D]))
         return prune_two_for_sby(cpi, bsize, x, xd, 1, 0);
       return prune_two_for_sby(cpi, bsize, x, xd, 1, 1);
       break;