Fix ptsname_r(3) return type to match glibc
The gHardy man pages specify the return type of ptsname_r to be char*, but the
return value to be 0 on success, negative on error and the gHardy stdlib.h
defines extern int ptsname_r(...).
Busybox telnetd fails to run successfully without this change.
diff --git a/libc/include/stdlib.h b/libc/include/stdlib.h
index acfe694..41e8d26 100644
--- a/libc/include/stdlib.h
+++ b/libc/include/stdlib.h
@@ -132,7 +132,7 @@
extern int unlockpt(int);
extern char* ptsname(int);
-extern char* ptsname_r(int, char*, size_t);
+extern int ptsname_r(int, char*, size_t);
extern int getpt(void);
static __inline__ int grantpt(int __fd)