Removed xalloc type functions from library

These xalloc functions are a private function for the library. If using
programs need them, then they should make their own error reporting or
use a common file.

proc/libprocfs.sym

@@ -71,11 +71,6 @@ global:
 	vm_pswpin;
 	vm_pswpout;
 	vminfo;
-	xalloc_err_handler;
-	xcalloc;
-	xmalloc;
-	xrealloc;
-	xstrdup;
 local:
 	*;
 };