make C function setgroups() be _setgroups(), called by the asm stub.

initgroups() can then use _setgroups() instead of setgroups().

lib/other/initgroups.c

@@ -2,6 +2,7 @@
 initgroups.c
 */
 #include <sys/param.h>
+#define setgroups _setgroups
 #include <unistd.h>
 #include <string.h>
 #include <grp.h>

lib/other/setgroups.c

@@ -3,6 +3,7 @@ setgroups.c
 */
 
 #include <lib.h>
+#define setgroups _setgroups
 #include <unistd.h>
 
 int setgroups(int ngroups, const gid_t *gidset)