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/spl/spl_dfu.c b/common/spl/spl_dfu.c
index 2c97473..05bb210 100644
--- a/common/spl/spl_dfu.c
+++ b/common/spl/spl_dfu.c
@@ -42,13 +42,13 @@
 	set_default_env(0);
 	str_env = env_get(dfu_alt_info);
 	if (!str_env) {
-		error("\"dfu_alt_info\" env variable not defined!\n");
+		pr_err("\"dfu_alt_info\" env variable not defined!\n");
 		return -EINVAL;
 	}
 
 	ret = env_set("dfu_alt_info", str_env);
 	if (ret) {
-		error("unable to set env variable \"dfu_alt_info\"!\n");
+		pr_err("unable to set env variable \"dfu_alt_info\"!\n");
 		return -EINVAL;
 	}