nvmem: core: return EFBIG on out-of-range write

When writing data that exceeds the nvmem size to a nvmem sysfs file
using the sh redirection operator >, the shell hangs, trying to
write the out-of-range bytes endlessly.

Fix the problem by returning EFBIG described in man 2 write.

Similar change was done for binary sysfs files on commit
0936896056365349afa867c16e9f9100a6707cbf

Signed-off-by: Guy Shapiro <guy.shapiro@mobi-wize.com>
Cc: linux-api@vger.kernel.org
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/nvmem/core.c

@@ -135,7 +135,7 @@ static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj,
 
 	/* Stop the user from writing */
 	if (pos >= nvmem->size)
-		return 0;
+		return -EFBIG;
 
 	if (count < nvmem->word_size)
 		return -EINVAL;