phosphor-pid-control: srcrev bump 91fe17f600..ad971e1b22

Patrick Venture (1):
      bugfix: add virtual destructor to zoneinterface

Change-Id: I888d91e7f60c5c77fb6ae5461e6ef46b49038dfc
Signed-off-by: Andrew Geissler <openbmcbump-github@yahoo.com>
diff --git a/recipes-phosphor/fans/phosphor-pid-control_git.bb b/recipes-phosphor/fans/phosphor-pid-control_git.bb
index a500af4..84fca86 100644
--- a/recipes-phosphor/fans/phosphor-pid-control_git.bb
+++ b/recipes-phosphor/fans/phosphor-pid-control_git.bb
@@ -13,7 +13,7 @@
 
 S = "${WORKDIR}/git"
 SRC_URI = "git://github.com/openbmc/phosphor-pid-control"
-SRCREV = "91fe17f600ed9a00778355b8bc0fd98766d214c8"
+SRCREV = "ad971e1b226f675fcae210f753b45ec4b7f86b04"
 
 # Each platform will need a service file that starts
 # at an appropriate time per system.  For instance, if