hiomap: Unblock SIGTERM on reset path

When IPMI is terminated, the SIGTERM signal was not re-enabled on the
hiomap's reset path, causing IPMI to not be terminated.

Tested:
- Without change:
Apr 16 20:46:43 witherspoon systemd[1]: Stopping Phosphor MBOX Daemon...
Apr 16 20:46:45 witherspoon ipmid[1471]: Blocked SIGTERM
...
Apr 16 20:47:15 witherspoon ipmid[1471]: Unblocked SIGTERM
Apr 16 20:48:15 witherspoon systemd[1]: phosphor-ipmi-host.service: State 'stop-sigterm' timed out. Killing.
Apr 16 20:48:15 witherspoon systemd[1]: phosphor-ipmi-host.service: Killing process 1471 (ipmid) with signal SIGKILL.

- With change:
Apr 16 21:11:23 witherspoon ipmid[1493]: Blocked SIGTERM
Apr 16 21:11:23 witherspoon ipmid[1493]: Received signal; quitting
Apr 16 21:11:23 witherspoon systemd[1]: Stopping Phosphor Inband IPMI...
Apr 16 21:11:23 witherspoon systemd[1]: Stopped Phosphor Inband IPMI.

Fixes: openbmc/openbmc#3465
Change-Id: Ie234b045664db4c63ba6674894be875d31d86cb4
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
diff --git a/hiomap.cpp b/hiomap.cpp
index 0c90a04..d29a0cb 100644
--- a/hiomap.cpp
+++ b/hiomap.cpp
@@ -387,6 +387,7 @@
 {
     // If this is running in signal context, ipmid will shutdown
     // the event queue as the last signal handler
+    sigtermResponse = SignalResponse::continueExecution;
     return 0;
 }
 
@@ -396,6 +397,7 @@
     {
         // If this is running in signal context, ipmid will shutdown
         // the event queue as the last signal handler
+        sigtermResponse = SignalResponse::continueExecution;
         return 0;
     }