bin/network/telnetd: Fix multiple definitions

Fix multiple definitions of 'terminaltype' and 'line' when linking.
Pointed out by gcc11.

Change-Id: I85552e2d243bd5db5f80806d92e6fa87bc41eb44
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3903
Reviewed-by: Jérôme Duval <[email protected]>

src/bin/network/telnetd/ext.h

@@ -62,7 +62,7 @@ extern int	auth_level;
 
 extern slcfun	slctab[NSLC + 1];	/* slc mapping table */
 
-char	*terminaltype;
+extern char	*terminaltype;
 
 /*
  * I/O data buffers, pointers, and counters.

src/bin/network/telnetd/sys_term.c

@@ -398,7 +398,6 @@ spcset(int func, cc_t *valp, cc_t **valpp)
  * Returns the file descriptor of the opened pty.
  */
 char alpha[] = "0123456789abcdefghijklmnopqrstuv";
-char line[16];
 
 int
 getpty(int *ptynum __unused)
@@ -1330,7 +1329,7 @@ scrub_env(void)
 
 	char **cpp, **cpp2;
 	const char **p;
- 
+
  	for (cpp2 = cpp = environ; *cpp; cpp++) {
 		int reject_it = 0;