Allow OSX fastboot to work with more devices.

ClearPipeStallBothEnds() appears to fail on some devices, but if we ignore
that error then fastboot does work. So ignore the error.

Change-Id: Ic866ece28a57c081e34079e1a032fa8155301ddf
diff --git a/fastboot/usb_osx.c b/fastboot/usb_osx.c
index 9488687..570a456 100644
--- a/fastboot/usb_osx.c
+++ b/fastboot/usb_osx.c
@@ -231,8 +231,7 @@
                 kr = (*interface)->ClearPipeStallBothEnds(interface,
                         handle->bulkIn);
                 if (kr != 0) {
-                    ERR("could not clear input pipe; result %d", kr);
-                    return -1;
+                    ERR("could not clear input pipe; result %x, ignoring...\n", kr);
                 }
             }
 
@@ -240,8 +239,7 @@
                 kr = (*interface)->ClearPipeStallBothEnds(interface,
                         handle->bulkOut);
                 if (kr != 0) {
-                    ERR("could not clear output pipe; result %d", kr);
-                    return -1;
+                    ERR("could not clear output pipe; result %x, ignoring....\n", kr);
                 }
             }