Make sure to define fd_open when not on Linux

My previous commit broke the build.  This was spotted by C.W. Betts.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5231 c046a42c-6fe2-441c-8c8c-71466251a162

block-raw-posix.c

@@ -1149,6 +1149,11 @@ static int raw_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
 }
 #else
 
+static int fd_open(BlockDriverState *bs)
+{
+    return 0;
+}
+
 static int raw_is_inserted(BlockDriverState *bs)
 {
     return 1;