Remove bashism in generating Version file

Signed-off-by: Garrett Cooper <yanegomi@gmail.com>
diff --git a/Makefile b/Makefile
index 90f171e..147fa62 100644
--- a/Makefile
+++ b/Makefile
@@ -173,7 +173,7 @@
 #
 .PHONY: Version
 Version:
-	if git describe &> /dev/null; then \
+	if git describe >/dev/null 2>&1; then \
 		git describe > "$@"; \
 	else \
 		cp VERSION "$@"; \