do not reference strdup() ! trying to fix the libs of the various config

* globals.c: do not reference strdup() !
* configure.in libxml-2.0.pc.in: trying to fix the libs
  of the various config extraction modules
Daniel
diff --git a/globals.c b/globals.c
index 2009c70..7d2ca4e 100644
--- a/globals.c
+++ b/globals.c
@@ -55,7 +55,7 @@
 xmlFreeFunc xmlFree = (xmlFreeFunc) free;
 xmlMallocFunc xmlMalloc = (xmlMallocFunc) malloc;
 xmlReallocFunc xmlRealloc = (xmlReallocFunc) realloc;
-xmlStrdupFunc xmlMemStrdup = (xmlStrdupFunc) strdup;
+xmlStrdupFunc xmlMemStrdup = (xmlStrdupFunc) xmlStrdup;
 #endif
 
 #include <libxml/threads.h>