dtlk: off by one in {read,write}_tts()

With a postfix increment retries is incremented beyond DTLK_MAX_RETRIES so
the error message is not displayed correctly.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: James R. Van Zandt <jrv@vanzandt.mv.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/dtlk.c

@@ -571,7 +571,7 @@ static char dtlk_read_tts(void)
 		portval = inb_p(dtlk_port_tts);
 	} while ((portval & TTS_READABLE) == 0 &&
 		 retries++ < DTLK_MAX_RETRIES);
-	if (retries == DTLK_MAX_RETRIES)
+	if (retries > DTLK_MAX_RETRIES)
 		printk(KERN_ERR "dtlk_read_tts() timeout\n");
 
 	ch = inb_p(dtlk_port_tts);	/* input from TTS port */
@@ -583,7 +583,7 @@ static char dtlk_read_tts(void)
 		portval = inb_p(dtlk_port_tts);
 	} while ((portval & TTS_READABLE) != 0 &&
 		 retries++ < DTLK_MAX_RETRIES);
-	if (retries == DTLK_MAX_RETRIES)
+	if (retries > DTLK_MAX_RETRIES)
 		printk(KERN_ERR "dtlk_read_tts() timeout\n");
 
 	TRACE_RET;
@@ -640,7 +640,7 @@ static char dtlk_write_tts(char ch)
 		while ((inb_p(dtlk_port_tts) & TTS_WRITABLE) == 0 &&
 		       retries++ < DTLK_MAX_RETRIES)	/* DT ready? */
 			;
-	if (retries == DTLK_MAX_RETRIES)
+	if (retries > DTLK_MAX_RETRIES)
 		printk(KERN_ERR "dtlk_write_tts() timeout\n");
 
 	outb_p(ch, dtlk_port_tts);	/* output to TTS port */