xtf: only set CC if it's not set

This prevents overwriting CC if it's already set on the environment.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>

diff --git a/build/common.mk b/build/common.mk
index 27415082e52af8124989c9425498751a277e2c0d..1120a167641244f09998303bf130770fed672e52 100644 (file)
--- a/build/common.mk
+++ b/build/common.mk
@@ -1,7 +1,7 @@
 ROOT := $(abspath $(CURDIR)/../..)
 DESTDIR ?= $(ROOT)/dist
 PREFIX ?= $(ROOT)
-CC = gcc
+CC ?= gcc
 
 ALL_CATEGORIES     := special functional xsa utility