git-svn: verify_ref() should actually --verify

Not sure how I missed this the first time around...
Signed-off-by: NEric Wong <normalperson@yhbt.net>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

git-svn.perl

@@ -1098,7 +1098,8 @@ sub read_uuid {
 
 sub verify_ref {
 	my ($ref) = @_;
-	eval { command_oneline([ 'rev-parse', $ref ], { STDERR => 0 }) };
+	eval { command_oneline([ 'rev-parse', '--verify', $ref ],
+	                       { STDERR => 0 }); };
 }
 
 sub repo_path_split {