spi: spidev_test: check error

Check the result of sscanf to verify a result was found.
report and error and abort if pattern was not found.

Signed-off-by: Joshua Clayton <stillcompiling@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

tools/spi/spidev_test.c

@@ -86,13 +86,17 @@ static void hex_dump(const void *src, size_t length, size_t line_size, char *pre
 static int unescape(char *_dst, char *_src, size_t len)
 {
 	int ret = 0;
+	int match;
 	char *src = _src;
 	char *dst = _dst;
 	unsigned int ch;
 
 	while (*src) {
 		if (*src == '\\' && *(src+1) == 'x') {
-			sscanf(src + 2, "%2x", &ch);
+			match = sscanf(src + 2, "%2x", &ch);
+			if (!match)
+				pabort("malformed input string");
+
 			src += 4;
 			*dst++ = (unsigned char)ch;
 		} else {