calloc.c: Remove use of register keyword

cpukit/libcsupport/src/calloc.c

@@ -6,7 +6,7 @@
  */
 
 /*
- *  COPYRIGHT (c) 1989-2007.
+ *  COPYRIGHT (c) 1989-2014.
  *  On-Line Applications Research Corporation (OAR).
  *
  *  The license and distribution terms for this file may be
@@ -28,7 +28,7 @@ void *calloc(
   size_t elsize
 )
 {
-  register char *cptr;
+  char   *cptr;
   size_t  length;
 
   MSBUMP(calloc_calls, 1);