mtd: spi-nor-core: Check for ctrlc() in spi_nor_erase()

May it possible to interrupt the spi_nor_erase() function.

Signed-off-by: Marek BehĂșn <marek.behun@nic.cz>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Masami Hiramatsu <masami.hiramatsu@linaro.org>
diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index 2c71866..a857599 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -929,6 +929,11 @@
 
 	while (len) {
 		WATCHDOG_RESET();
+		if (ctrlc()) {
+			addr_known = false;
+			ret = -EINTR;
+			goto erase_err;
+		}
 #ifdef CONFIG_SPI_FLASH_BAR
 		ret = write_bar(nor, addr);
 		if (ret < 0)