treewide: replace with error() with pr_err()

U-Boot widely uses error() as a bit noisier variant of printf().

This macro causes name conflict with the following line in
include/linux/compiler-gcc.h:

  # define __compiletime_error(message) __attribute__((error(message)))

This prevents us from using __compiletime_error(), and makes it
difficult to fully sync BUILD_BUG macros with Linux.  (Notice
Linux's BUILD_BUG_ON_MSG is implemented by using compiletime_assert().)

Let's convert error() into now treewide-available pr_err().

Done with the help of Coccinelle, excluing tools/ directory.

The semantic patch I used is as follows:

// <smpl>
@@@@
-error
+pr_err
 (...)
// </smpl>

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
[trini: Re-run Coccinelle]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/common/dfu.c b/common/dfu.c
index 546a1ab..07dff31 100644
--- a/common/dfu.c
+++ b/common/dfu.c
@@ -26,13 +26,13 @@
 
 	ret = board_usb_init(usbctrl_index, USB_INIT_DEVICE);
 	if (ret) {
-		error("board usb init failed\n");
+		pr_err("board usb init failed\n");
 		return CMD_RET_FAILURE;
 	}
 	g_dnl_clear_detach();
 	ret = g_dnl_register(usb_dnl_gadget);
 	if (ret) {
-		error("g_dnl_register failed");
+		pr_err("g_dnl_register failed");
 		return CMD_RET_FAILURE;
 	}
 
@@ -75,7 +75,7 @@
 			ret = dfu_flush(dfu_get_defer_flush(), NULL, 0, 0);
 			dfu_set_defer_flush(NULL);
 			if (ret) {
-				error("Deferred dfu_flush() failed!");
+				pr_err("Deferred dfu_flush() failed!");
 				goto exit;
 			}
 		}