[gdb/tui] Simplify tui_puts_internal

Simplify tui_puts_internal by using continue, as per this [1] coding standard
rule, making the function more readable and easier to understand.

No functional changes.

Tested on x86_64-linux.

[1] https://llvm.org/docs/CodingStandards.html#use-early-exits-and-continue-to-simplify-code

Reviewed-By: Tom Tromey <tom@tromey.com>
diff --git a/gdb/tui/tui-io.c b/gdb/tui/tui-io.c
index 908cb83..8cb68d1 100644
--- a/gdb/tui/tui-io.c
+++ b/gdb/tui/tui-io.c
@@ -523,36 +523,37 @@ tui_puts_internal (WINDOW *w, const char *string, int *height)
 
   while ((c = *string++) != 0)
     {
-      if (c == '\n')
-	saw_nl = true;
-
       if (c == '\1' || c == '\2')
 	{
 	  /* Ignore these, they are readline escape-marking
 	     sequences.  */
+	  continue;
 	}
-      else
-	{
-	  if (c == '\033')
-	    {
-	      size_t bytes_read = apply_ansi_escape (w, string - 1);
-	      if (bytes_read > 0)
-		{
-		  string = string + bytes_read - 1;
-		  continue;
-		}
-	    }
-	  do_tui_putc (w, c);
 
-	  if (height != nullptr)
+      if (c == '\033')
+	{
+	  size_t bytes_read = apply_ansi_escape (w, string - 1);
+	  if (bytes_read > 0)
 	    {
-	      int col = getcurx (w);
-	      if (col <= prev_col)
-		++*height;
-	      prev_col = col;
+	      string = string + bytes_read - 1;
+	      continue;
 	    }
 	}
+
+      if (c == '\n')
+	saw_nl = true;
+
+      do_tui_putc (w, c);
+
+      if (height != nullptr)
+	{
+	  int col = getcurx (w);
+	  if (col <= prev_col)
+	    ++*height;
+	  prev_col = col;
+	}
     }
+
   if (TUI_CMD_WIN != nullptr && w == TUI_CMD_WIN->handle.get ())
     update_cmdwin_start_line ();
   if (saw_nl)