TUN-8134: Revert installed prefix to /usr

Author: chungthuang

Makefile

@@ -46,7 +46,7 @@ endif
 
 IMPORT_PATH    := github.com/cloudflare/cloudflared
 PACKAGE_DIR    := $(CURDIR)/packaging
-PREFIX         := /usr/local
+PREFIX         := /usr
 INSTALL_BINDIR := $(PREFIX)/bin/
 INSTALL_MANDIR := $(PREFIX)/share/man/man1/