libprocessgroup: Use pid_t consistently for PIDs

Test: m
Change-Id: Ibcef6b73a8fd3088c88b822a6b33d005595488b2
diff --git a/libprocessgroup/task_profiles.cpp b/libprocessgroup/task_profiles.cpp
index eaafa5e..05927cb 100644
--- a/libprocessgroup/task_profiles.cpp
+++ b/libprocessgroup/task_profiles.cpp
@@ -489,7 +489,7 @@
 }
 
 bool WriteFileAction::WriteValueToFile(const std::string& value_, ResourceCacheType cache_type,
-                                       uid_t uid, int pid, bool logfailures) const {
+                                       uid_t uid, pid_t pid, bool logfailures) const {
     std::string value(value_);
 
     value = StringReplace(value, "<uid>", std::to_string(uid), true);
@@ -564,7 +564,7 @@
     DIR* d;
     struct dirent* de;
     char proc_path[255];
-    int t_pid;
+    pid_t t_pid;
 
     sprintf(proc_path, "/proc/%d/task", pid);
     if (!(d = opendir(proc_path))) {