scripted-diff: Rename Sock::{RECV,SEND,ERR}

The `ERR` macro is defined on illumos-based systems in the `regset.h`
header included by the Boost.Test framework, which causes a compilation
error.

-BEGIN VERIFY SCRIPT-

ren1() { sed -i "s/\<$1\>/$2/g" $( git grep -l "$1" ./src/util/sock.* ./src/httpserver.h ) ; }
ren1 RECV RecvEvent
ren1 SEND SendEvent
ren1 ERR  ErrorEvent

ren2() { sed -i "s/\<$1\>/$2/g" $( git grep -l "$1" ./src/ ) ; }
ren2 Sock::RECV Sock::RecvEvent
ren2 Sock::SEND Sock::SendEvent
ren2 Sock::ERR  Sock::ErrorEvent

-END VERIFY SCRIPT-

src/test/pcp_tests.cpp

@@ -191,14 +191,14 @@ public:
               Event* occurred = nullptr) const override
     {
         // Only handles receive events.
-        if (AtEndOfScript() || requested != Sock::RECV) {
+        if (AtEndOfScript() || requested != Sock::RecvEvent) {
             m_clock += timeout;
         } else {
             std::chrono::milliseconds delay = std::min(m_time_left, timeout);
             m_clock += delay;
             m_time_left -= delay;
             if (CurOp().op == TestOp::RECV && m_time_left == 0s && occurred != nullptr) {
-                *occurred = Sock::RECV;
+                *occurred = Sock::RecvEvent;
             }
             if (CurOp().op == TestOp::NOP) {
                 // This was a pure delay operation, move to the next op.