print pid in ProcessInfo lookup error messages

Summary:
It would be helpful to see the pid of the process when we fail to get the process name

Created from CodeHub with https://fburl.com/edit-in-codehub

Reviewed By: kavehahmadi60

Differential Revision: D59873146

fbshipit-source-id: 8d85320688372a5a014e39ecb1aa32ae1b8eac32

eden/common/utils/ProcessInfo.cpp

@@ -352,12 +352,20 @@ ProcessSimpleName readProcessSimpleName([[maybe_unused]] pid_t pid) {
   auto ret = proc_name(pid, namePtr, len);
   if (ret > len) {
     // This should never happen.
-    XLOGF(INFO, "proc_name returned length greater than provided buffer.");
+    XLOGF(
+        INFO,
+        "proc_name for pid {} returned length greater than provided buffer.",
+        pid);
   } else if (ret != 0) {
     name.resize(ret);
     return ProcessSimpleName(std::string(name.begin(), name.end()));
   } else {
-    XLOGF(DBG2, "proc_name failed: {} ({})", folly::errnoStr(errno), errno);
+    XLOGF(
+        DBG2,
+        "proc_name failed for pid {}: {} ({})",
+        pid,
+        folly::errnoStr(errno),
+        errno);
   }
 #endif