test: fix output redirection [shellcheck]

SC2069: The order of the 2>&1 and the redirect matters.  The 2>&1 has to be
last.

Maintainer propsed stderr should be visible, see review link for details.

Reference; https://github.com/koalaman/shellcheck/wiki/SC2069
Review: https://github.com/logrotate/logrotate/pull/138


Signed-off-by: Sami Kerola <kerolasa@iki.fi>

Closes #138

test/test-common.sh

@@ -143,7 +143,7 @@ checkoutput() {
 	    echo expected: \'$expected\'
 	    exit 2
 	fi
-	echo "$config_crc" | md5sum -c - 2>&1 > /dev/null
+	echo "$config_crc" | md5sum -c - >/dev/null
 	if [ $? != 0 ]; then
 		echo "config file $output has been altered: MD5 sum mismatch"
 		exit 3