USB: fix create_pipe()

create_pipe() can give wrong result if an expression is passed as the 'endpoint'
argument -- due to missing parentheses.

Thanks to Martin Mueller for finding the bug and providing the patch.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
diff --git a/include/usb.h b/include/usb.h
index a1f09d4..bc4ccfe 100644
--- a/include/usb.h
+++ b/include/usb.h
@@ -259,7 +259,7 @@
  */
 /* Create various pipes... */
 #define create_pipe(dev,endpoint) \
-		(((dev)->devnum << 8) | (endpoint << 15) | \
+		(((dev)->devnum << 8) | ((endpoint) << 15) | \
 		((dev)->speed << 26) | (dev)->maxpacketsize)
 #define default_pipe(dev) ((dev)->speed << 26)