env_nand: Use nand_read_skip_bad instead of nand_read

The nand-read function returns an error code if correctable errors have occurred.
This is not desirable, since the errors have been corrected!

This patch switches to the nand_read_skip_bad function which does not
return an error code if the errors are correctable.

Signed-off-by: Steve Sakoman <steve.sakoman@linaro.org>
Acked-by: Scott Wood <scottwood@freescale.com>

common/env_nand.c

@@ -297,7 +297,7 @@ int readenv(size_t offset, u_char * buf)
 			offset += blocksize;
 		} else {
 			char_ptr = &buf[amount_loaded];
-			if (nand_read(&nand_info[0], offset, &len, char_ptr))
+			if (nand_read_skip_bad(&nand_info[0], offset, &len, char_ptr))
 				return 1;
 			offset += blocksize;
 			amount_loaded += len;