[Fix] lpcsnoop service exit unsuccessfully

[Issue] when BMC code reset, the lpcsnoop service exit unsuccessfully.

[Root Cause] return exit code 1 when caught SIGTERM signal.

https://github.com/openbmc/phosphor-host-postd/blob/master/main.cpp#L368
https://github.com/openbmc/sdeventplus/blob/master/src/sdeventplus/event.hpp#L115

Tested:
Service exit successfully

Signed-off-by: Sunita Kumari <sunitax.kumari@intel.com>
Change-Id: I47cc6d31742f1595231fe22e345ea955ad41c377
diff --git a/main.cpp b/main.cpp
index 57897f9..c294a13 100644
--- a/main.cpp
+++ b/main.cpp
@@ -320,7 +320,6 @@
 #endif
 
 #ifndef ENABLE_IPMI_SNOOP
-    int rc = 0;
 
     bool deferSignals = true;
 
@@ -365,7 +364,7 @@
                 ;
 
             // Run and never timeout
-            rc = event.run(std::nullopt);
+            event.run(std::nullopt);
         }
     }
     catch (const std::exception& e)
@@ -378,6 +377,6 @@
         close(postFd);
     }
 
-    return rc;
+    return 0;
 #endif
 }