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/adc/sandbox.c b/drivers/adc/sandbox.c
index 3718922..80e8e37 100644
--- a/drivers/adc/sandbox.c
+++ b/drivers/adc/sandbox.c
@@ -61,7 +61,7 @@
 	/* For single-channel conversion mode, check if channel was selected */
 	if ((priv->conversion_mode == SANDBOX_ADC_MODE_SINGLE_CHANNEL) &&
 	    !(priv->active_channel_mask & (1 << channel))) {
-		error("Request for an inactive channel!");
+		pr_err("Request for an inactive channel!");
 		return -EINVAL;
 	}
 
@@ -82,12 +82,12 @@
 
 	/* Return error for single-channel conversion mode */
 	if (priv->conversion_mode == SANDBOX_ADC_MODE_SINGLE_CHANNEL) {
-		error("ADC in single-channel mode!");
+		pr_err("ADC in single-channel mode!");
 		return -EPERM;
 	}
 	/* Check channel selection */
 	if (!(priv->active_channel_mask & channel_mask)) {
-		error("Request for an inactive channel!");
+		pr_err("Request for an inactive channel!");
 		return -EINVAL;
 	}
 	/* The conversion must be started before reading the data */