n_tty: invert TTY_NORMAL condition in n_tty_receive_buf_standard

Handle !TTY_NORMAL as a short path and 'continue' the loop. Do the rest as
a normal code flow. This decreases the indentation level by one and
makes the code flow more understandable.

IOW, we avoid
  if (cond) {
    LONG CODE;
  } else
    single_line();
by
  if (!cond) {
    single_line();
    continue;
  }
  LONG CODE;

While at it, invert also the 'if (!test_bit) A else B' into 'if
(test_bit) B else A'.

Signed-off-by: Jiri Slaby <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

drivers/tty/n_tty.c

@@ -1541,21 +1541,24 @@ static void n_tty_receive_buf_standard(struct tty_struct *tty,
 			continue;
 		}
 
-		if (likely(flag == TTY_NORMAL)) {
-			if (I_ISTRIP(tty))
-				c &= 0x7f;
-			if (I_IUCLC(tty) && L_IEXTEN(tty))
-				c = tolower(c);
-			if (L_EXTPROC(tty)) {
-				put_tty_queue(c, ldata);
-				continue;
-			}
-			if (!test_bit(c, ldata->char_map))
-				n_tty_receive_char(tty, c);
-			else
-				n_tty_receive_char_special(tty, c);
-		} else
+		if (unlikely(flag != TTY_NORMAL)) {
 			n_tty_receive_char_flagged(tty, c, flag);
+			continue;
+		}
+
+		if (I_ISTRIP(tty))
+			c &= 0x7f;
+		if (I_IUCLC(tty) && L_IEXTEN(tty))
+			c = tolower(c);
+		if (L_EXTPROC(tty)) {
+			put_tty_queue(c, ldata);
+			continue;
+		}
+
+		if (test_bit(c, ldata->char_map))
+			n_tty_receive_char_special(tty, c);
+		else
+			n_tty_receive_char(tty, c);
 	}
 }