qapi: add "unix" to the set of reserved words

It is #defined to 1.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
diff --git a/scripts/qapi.py b/scripts/qapi.py
index 057332e..afc5f32 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -156,7 +156,9 @@
     # GCC http://gcc.gnu.org/onlinedocs/gcc-4.7.1/gcc/C-Extensions.html
     # excluding _.*
     gcc_words = set(['asm', 'typeof'])
-    if protect and (name in c89_words | c99_words | c11_words | gcc_words):
+    # namespace pollution:
+    polluted_words = set(['unix'])
+    if protect and (name in c89_words | c99_words | c11_words | gcc_words | polluted_words):
         return "q_" + name
     return name.replace('-', '_').lstrip("*")