console: Fix console_putchar() for CSI J

It falls through to the code for CSI K.  "Erase Down" also does "Erase
End of Line", "Erase Up" also does "Erase Start of Line", and "Erase
Screen" also does "Erase Line".  Happens not to be visible.  Fix it
anyway.  Spotted by Coverity.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

console.c

@@ -1011,6 +1011,7 @@ static void console_putchar(TextConsole *s, int ch)
                     }
                     break;
                 }
+                break;
             case 'K':
                 switch (s->esc_params[0]) {
                 case 0: