git-merge: minor fix for no_trivial_merge_strategies.

The shell loop to determine if we should skip the trivial
in-index merge stage based on what strategy is given was not
prepared to have more than one strategy listed in the variable
$no_trivial_merge_strategies.

This does not trigger unless you use a modified git but the fix
is simple and straightforward, so let's fix it before 1.5.0.1.

Signed-off-by: Junio C Hamano <junkio@cox.net>

git-merge.sh

@@ -254,12 +254,15 @@ esac
 
 for s in $use_strategies
 do
-	case " $s " in
-	*" $no_trivial_merge_strategies "*)
-		index_merge=f
-		break
-		;;
-	esac
+	for nt in $no_trivial_merge_strategies
+	do
+		case " $s " in
+		*" $nt "*)
+			index_merge=f
+			break
+			;;
+		esac
+	done
 done
 
 case "$#" in