Don't override CC in example Makefile
bitbake discards overrides like this away, but for
builds using the SDK CC needs to be picked up from
the environment.
diff --git a/common/recipes-phosphor/obmc-phosphor-fan/files/Makefile b/common/recipes-phosphor/obmc-phosphor-fan/files/Makefile
index 8ca27e4..10e3fa2 100644
--- a/common/recipes-phosphor/obmc-phosphor-fan/files/Makefile
+++ b/common/recipes-phosphor/obmc-phosphor-fan/files/Makefile
@@ -1,7 +1,7 @@
EXE = obmc-phosphor-fand
OBJS = $(EXE).o
DEPPKGS = gio-unix-2.0 glib-2.0
-CC = $(CROSS_COMPILE)gcc
+CC ?= $(CROSS_COMPILE)gcc
INCLUDES += $(shell pkg-config --cflags $(DEPPKGS))
LIBS += $(shell pkg-config --libs $(DEPPKGS))