Correctly expand awk variable

Author: enekochan

Makefile.common

@@ -49,7 +49,7 @@ ifeq (${shell uname}, Darwin)
  # If AVR Toolchain was installed from Microchip binaries
  ifneq (, $(shell which avr-gcc))
   CC			= clang
-  AVR_ROOT 	:= $(shell which avr-gcc | awk -F'bin/' '{ print $1 }')
+  AVR_ROOT 	:= $(shell which avr-gcc | awk -F'bin/' '{ print $$1 }')
   AVR 		:= ${AVR_ROOT}/bin/avr-
  else
   # gcc 4.2 from MacOS is really not up to scratch anymore