macosx: fixed crash when opening DVDs with uncommon disk names (close #7146)

(cherry picked from commit 68889de9bd2481b86c44e4d4150bbad19ffd5416)

modules/gui/macosx/open.m

@@ -708,13 +708,13 @@ static VLCOpen *_o_sharedMainInstance = nil;
 
     GetVolParmsInfoBuffer volumeParms;
     err = FSGetVolumeParms( actualVolume, &volumeParms, sizeof(volumeParms) );
-    if ( noErr != err ) {
-        msg_Err( p_intf, "error retrieving volume params, bailing out" );
-        return @"";
-    }
-
+    if ( noErr == err )
+    {
         NSString *bsdName = [NSString stringWithUTF8String:(char *)volumeParms.vMDeviceID];
         return [NSString stringWithFormat:@"/dev/r%@", bsdName];
+    }
+
+    return @"";
 }
 
 - (char *)getVolumeTypeFromMountPath:(NSString *)mountPath