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/exynos-adc.c b/drivers/adc/exynos-adc.c
index 324d72f..3bb065d 100644
--- a/drivers/adc/exynos-adc.c
+++ b/drivers/adc/exynos-adc.c
@@ -22,7 +22,7 @@
 	struct exynos_adc_v2 *regs = priv->regs;
 
 	if (channel != priv->active_channel) {
-		error("Requested channel is not active!");
+		pr_err("Requested channel is not active!");
 		return -EINVAL;
 	}
 
@@ -80,7 +80,7 @@
 
 	/* Check HW version */
 	if (readl(&regs->version) != ADC_V2_VERSION) {
-		error("This driver supports only ADC v2!");
+		pr_err("This driver supports only ADC v2!");
 		return -ENXIO;
 	}
 
@@ -109,7 +109,7 @@
 
 	priv->regs = (struct exynos_adc_v2 *)devfdt_get_addr(dev);
 	if (priv->regs == (struct exynos_adc_v2 *)FDT_ADDR_T_NONE) {
-		error("Dev: %s - can't get address!", dev->name);
+		pr_err("Dev: %s - can't get address!", dev->name);
 		return -ENODATA;
 	}