contrib/chg/Makefile

--- a/contrib/chg/Makefile	Sun Mar 20 15:25:25 2016 -0700
+++ b/contrib/chg/Makefile	Sun Mar 20 15:43:20 2016 -0700
@@ -7,6 +7,9 @@
 CFLAGS ?= -O2 -Wall -Wextra -pedantic -g
 CPPFLAGS ?= -D_FORTIFY_SOURCE=2
 override CFLAGS += -std=gnu99
+ifdef HGPATH
+override CPPFLAGS += -DHGPATH=\"$(HGPATH)\"
+endif
 
 DESTDIR =
 PREFIX = /usr/local