fbcode_builder: update current commit for iproute2
fbcode_builder: update current commit for iproute2

Summary:
The manifest file for iproute2 previously listed the commit to check out as
7ca63aef7d1b0c808da0040c6b366ef7a61f38c1.  However, this is not a commit, but
a tag object that refers to commit 92a0236a3cdf3438000834121b7ea8a09f1f52b1.

This caused getdeps to think that iproute2 was always out-of-date, even when
it was already on the correct commit, since it was comparing current commit ID
against the tag ID.

This updates the manifest to refer to the commit ID instead of the tag ID.

Reviewed By: shri-khare

Differential Revision: D17005418

fbshipit-source-id: c7145c73b66ae93a2e9097ddcf8c53237b135d32

facebook/wangle,facebook/wangle,facebook/wangle