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/arm/pl011/aarch32/pl011_console.S b/drivers/arm/pl011/aarch32/pl011_console.S
index 93045f0..9caeb0c 100644
--- a/drivers/arm/pl011/aarch32/pl011_console.S
+++ b/drivers/arm/pl011/aarch32/pl011_console.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016-2019, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2020, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -222,17 +222,19 @@
 endfunc console_pl011_getc
 
 	/* ---------------------------------------------
-	 * int console_core_flush(uintptr_t base_addr)
+	 * void console_core_flush(uintptr_t base_addr)
 	 * 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
 	 * ---------------------------------------------
 	 */
 func console_pl011_core_flush
+#if ENABLE_ASSERTIONS
 	cmp	r0, #0
-	beq	flush_error
+	ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
 
 1:
 	/* Loop while the transmit FIFO is busy */
@@ -240,19 +242,15 @@
 	tst	r1, #PL011_UARTFR_BUSY
 	bne	1b
 
-	mov	r0, #0
-	bx	lr
-flush_error:
-	mov	r0, #-1
 	bx	lr
 endfunc console_pl011_core_flush
 
 	/* ---------------------------------------------
-	 * int console_pl011_flush(console_t *console)
+	 * void console_pl011_flush(console_t *console)
 	 * Function to force a write of all buffered
 	 * data that hasn't been output.
 	 * In : r0 - pointer to console_t structure
-	 * Out : return -1 on error else return 0.
+	 * Out : void
 	 * Clobber list: r0, r1
 	 * ---------------------------------------------
 	 */