Don't return error information from console_flush

And from crash_console_flush.

We ignore the error information return by console_flush in _every_
place where we call it, and casting the return type to void does not
work around the MISRA violation that this causes. Instead, we collect
the error information from the driver (to avoid changing that API), and
don't return it to the caller.

Change-Id: I1e35afe01764d5c8f0efd04f8949d333ffb688c1
Signed-off-by: Jimmy Brisson <jimmy.brisson@arm.com>
diff --git a/drivers/imx/uart/imx_uart.c b/drivers/imx/uart/imx_uart.c
index 2c9652d..dfe2e92 100644
--- a/drivers/imx/uart/imx_uart.c
+++ b/drivers/imx/uart/imx_uart.c
@@ -171,12 +171,11 @@
  * Function to force a write of all buffered
  * data that hasn't been output.
  * In : r0 - console base address
- * Out : return -1 on error else return 0.
+ * Out : void
  * Clobber list : r0, r1
  * ---------------------------------------------
  */
-int console_imx_uart_core_flush(uintptr_t base_addr)
+void console_imx_uart_core_flush(uintptr_t base_addr)
 {
-	return 0;
 }