lib/failure.c: Replace strncpy(3) call by STRTCPY()

This call was way too clever.  It relied on the last byte of fail_line
being 0 due to it being in a static structure and never writing to it.
Write an explicit terminating null byte, by using STRTCPY().

Cc: Matthew House <mattlloydhouse@gmail.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

lib/failure.c

@@ -19,6 +19,7 @@
 #include "failure.h"
 #include "memzero.h"
 #include "prototypes.h"
+#include "strtcpy.h"
 
 
 #define	YEAR	(365L*DAY)
@@ -78,7 +79,7 @@ void failure (uid_t uid, const char *tty, struct faillog *fl)
 		fl->fail_cnt++;
 	}
 
-	strncpy (fl->fail_line, tty, sizeof (fl->fail_line) - 1);
+	STRTCPY(fl->fail_line, tty);
 	(void) time (&fl->fail_time);
 
 	/*