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/drivers/usb/gadget/f_fastboot.c b/drivers/usb/gadget/f_fastboot.c
index f3382a9..7acffb6 100644
--- a/drivers/usb/gadget/f_fastboot.c
+++ b/drivers/usb/gadget/f_fastboot.c
@@ -410,7 +410,7 @@
 
 	strsep(&cmd, ":");
 	if (!cmd) {
-		error("missing variable");
+		pr_err("missing variable");
 		fastboot_tx_write_str("FAILmissing var");
 		return;
 	}
@@ -593,7 +593,7 @@
 
 	strsep(&cmd, ":");
 	if (!cmd) {
-		error("missing partition name");
+		pr_err("missing partition name");
 		fastboot_tx_write_str("FAILmissing partition name");
 		return;
 	}
@@ -645,7 +645,7 @@
 
 	strsep(&cmd, ":");
 	if (!cmd) {
-		error("missing partition name");
+		pr_err("missing partition name");
 		fastboot_tx_write_str("FAILmissing partition name");
 		return;
 	}
@@ -718,7 +718,7 @@
 	}
 
 	if (!func_cb) {
-		error("unknown command: %.*s", req->actual, cmdbuf);
+		pr_err("unknown command: %.*s", req->actual, cmdbuf);
 		fastboot_tx_write_str("FAILunknown command");
 	} else {
 		if (req->actual < req->length) {
@@ -726,7 +726,7 @@
 			buf[req->actual] = 0;
 			func_cb(ep, req);
 		} else {
-			error("buffer overflow");
+			pr_err("buffer overflow");
 			fastboot_tx_write_str("FAILbuffer overflow");
 		}
 	}