avoid compile error when <pthread.h> is absent

* src/internal.h (HAVE_PTHREAD_H): Test with "#ifdef", not "#if".

ChangeLog

+Fri Apr 18 11:24:24 CEST 2008 Jim Meyering <meyering@redhat.com>
+
+	avoid compile error when <pthread.h> is absent
+	* src/internal.h (HAVE_PTHREAD_H): Test with "#ifdef", not "#if".
+
 Fri Apr 18 09:27:00 BST 2008 Richard W.M. Jones <rjones@redhat.com>
 
 	Fixes for MinGW.

src/internal.h

@@ -12,7 +12,7 @@
 #include <sys/syslimits.h>
 #endif
 
-#if HAVE_PTHREAD_H
+#ifdef HAVE_PTHREAD_H
 #include <pthread.h>
 #define PTHREAD_MUTEX_T(v) pthread_mutex_t v
 #else