SCRIPTS: git-show-backports: make -m most only show the left branch

We've never used the output of the rightmost branch with this tool,
and it systematically causes two identical outputs making the job
harder during backport sessions. Let's simply remove the right part
when it's identical to the left one. This also adds a few line feeds
to make the output more readable.

(cherry picked from commit f456f6f2a36f0e2ce82ef80819974cb9dc8b4e86)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit 2a53511500609a57c40bf0a33219954d45d6a31d)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit fe6494a26f6876defa806800d4a84f9c58485c3a)
Signed-off-by: Willy Tarreau <w@1wt.eu>
diff --git a/scripts/git-show-backports b/scripts/git-show-backports
index 0fad6c1..2a3f468 100755
--- a/scripts/git-show-backports
+++ b/scripts/git-show-backports
@@ -249,12 +249,18 @@
 		echo "No missing commit to apply."
 	elif [ -n "$MISSING" ]; then
 		echo
+		echo
 		echo "In order to show and/or apply all leftmost commits to current branch :"
 		echo "   git show ${left_commits[@]}"
+		echo
 		echo "   git cherry-pick -sx ${left_commits[@]}"
 		echo
-		echo "In order to show and/or apply all rightmost commits to current branch :"
-		echo "   git show ${right_commits[@]}"
-		echo "   git cherry-pick -sx ${right_commits[@]}"
+		if [ "${left_commits[*]}" != "${right_commits[*]}" ]; then
+			echo "In order to show and/or apply all rightmost commits to current branch :"
+			echo "   git show ${right_commits[@]}"
+			echo
+			echo "   git cherry-pick -sx ${right_commits[@]}"
+			echo
+		fi
 	fi
 )