Makes sure to check any return values

The return value of any function should be checked if that function
uses the return value to provide some sort of status information.

Signed-off-by: Erik Hovland <erik@hovland.org>
Signed-off-by: Dan Dennedy <dan@dennedy.org>

tools/testlibraw.c

@@ -180,7 +180,8 @@ int main(int argc, char **argv)
                         perror("failed");
                         continue;
                 }
-                raw1394_loop_iterate(handle);
+                if (raw1394_loop_iterate(handle))
+			perror("failed");
         }
 
         printf("\nusing standard tag handler and synchronous calls\n");