make: avo_alloca.h works around a very old Solaris bug, delete it

@@ -30,11 +30,11 @@
  */
 
 /*
  * Included files
  */
-#include <avo/avo_alloca.h>             /* alloca() */
+#include <alloca.h>             /* alloca() */
 #if defined(TEAMWARE_MAKE_CMN)
 #include <avo/util.h>           /* avo_get_user(), avo_hostname() */
 #endif
 
 #if defined(DISTRIBUTED) || defined(MAKETOOL) /* tolik */