Use the appropriate i686 or x86_64 mingw-w64 triple

Test: ./checkbuild.py --system=windows
Test: ./checkbuild.py --system=windows64
Change-Id: Ib39fc3611f7a8c43eb299bfd5980a42537cfad71
diff --git a/build-yasm.sh b/build-yasm.sh
index 0fd897d..86e50f2 100755
--- a/build-yasm.sh
+++ b/build-yasm.sh
@@ -94,13 +94,8 @@
 fail_panic "Could not copy yasm sources to: $BUILD_DIR/src"
 
 CONFIGURE_FLAGS="--disable-nls --disable-rpath --prefix=$BUILD_DIR/prefix"
-if [ "$MINGW" = "yes" ]; then
-    # Required for a proper mingw cross compile
-    CONFIGURE_FLAGS=$CONFIGURE_FLAGS" --host=i586-pc-mingw32"
-fi
-
-if [ "$DARWIN" = "yes" ]; then
-    # Required for a proper darwin cross compile
+if [ "$MINGW" = "yes" -o "$DARWIN" = "yes" ]; then
+    # Required for a proper mingw or darwin cross compile
     CONFIGURE_FLAGS=$CONFIGURE_FLAGS" --host=$ABI_CONFIGURE_HOST"
 fi