libselinux: Change annotation on include/selinux/avc.h to avoid upsetting SWIG

The earlier patch to avc.c put the struct member annotation at
the end of the line, which works fine for GCC, but upsets SWIG.
Equivalent code in selinux.h demonstrates how to place the
annotation without upsetting SWIG.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Dan Walsh <dwalsh@redhat.com>

libselinux/include/selinux/avc.h

@@ -130,7 +130,11 @@ struct avc_memory_callback {
 
 struct avc_log_callback {
 	/* log the printf-style format and arguments. */
-	void (*func_log) (const char *fmt, ...) __attribute__((__format__(printf, 1, 2)));
+	void
+#ifdef __GNUC__
+__attribute__ ((format(printf, 1, 2)))
+#endif
+	(*func_log) (const char *fmt, ...);
 	/* store a string representation of auditdata (corresponding
 	   to the given security class) into msgbuf. */
 	void (*func_audit) (void *auditdata, security_class_t cls,