xcompile: Get rid of $ARMFLAGS

Whatever this variable was intended for, it doesn't appear to have
any purpose now.

BUG=none
BRANCH=none
TEST=buildgcc -p armv7a-eabi still works

Signed-off-by: David Hendricks <dhendrix@chromium.org>
Change-Id: I618c6c05c95face6c902e626a3574700bea12153
Reviewed-on: https://chromium-review.googlesource.com/208145
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>

util/xcompile/xcompile

@@ -113,8 +113,7 @@ detect_special_flags() {
 		CFLAGS="$CFLAGS  -march=i686"
 		;;
 	arm )
-		ARMFLAGS=""
-		testcc "$CC" "$CFLAGS $ARMFLAGS" && CFLAGS="$CFLAGS $ARMFLAGS"
+		testcc "$CC" "$CFLAGS" && CFLAGS="$CFLAGS"
 		;;
 	esac
 }