Linux: Added support for gcc-4.9.1

Fixed bug with missing quote in #error found by gcc 4.9.1

Signed-off-by: Mark Charlebois <charlebm@gmail.com>

makefiles/toolchain_native.mk

@@ -62,6 +62,8 @@ CLANGVER=
 endif
 endif
 
+USE_GCC=1
+
 ifeq ($(USE_GCC),1)
 # GCC Options:
 CC			 = gcc
@@ -69,7 +71,7 @@ CXX			 = g++
 CPP			 = gcc -E
 
 # GCC Version
-DEV_VER_SUPPORTED	 = 4.6 4.8.2
+DEV_VER_SUPPORTED	 = 4.6 4.8.2 4.9.1
 
 else
 # Clang options

src/platforms/px4_workqueue.h

@@ -35,8 +35,8 @@
 
 #pragma once
 
-#ifdef __PX4_ROS
-#error "Work queue not supported on ROS
+#if defined(__PX4_ROS)
+#error "Work queue not supported on ROS"
 #elif defined(__PX4_NUTTX)
 #include <nuttx/arch.h>
 #include <nuttx/wqueue.h>