Update revision for PNaCl

Update db7f23a6d9fd2d1673de75dd464930c080f88987 -> 26f5754ba5af5b6fc94c998555719753824700fe

Pull the following PNaCl changes into NaCl:
  26f5754: (sbc@chromium.org) Revert "Implement pthread_rwlock functions for NaCl newlib."

BUG= https://code.google.com/p/nativeclient/issues/detail?id=4105
R= sbc@chromium.org
TEST=git cl try
(Please LGTM this change and tick the "commit" box)

Review URL: https://codereview.chromium.org/954743002
3 files changed