malloc.h is not standard, even on sparc

Index: cextern/cfitsio/lib/eval_defs.h
--- cextern/cfitsio/lib/eval_defs.h.orig
+++ cextern/cfitsio/lib/eval_defs.h
@@ -5,9 +5,6 @@
 #if defined(__sgi) || defined(__hpux)
 #include <alloca.h>
 #endif
-#ifdef sparc
-#include <malloc.h>
-#endif
 #include "fitsio2.h"
 
 #define MAXDIMS       5
