Use POSIX pid_t and not lldb::pid_t.

The latter is uint64_t beacuse lldb supports arbitrary pid/platforms
but in this case we're using it as return value for fork() which might
return -1 to the parent in case the syscall fails. 

Differential Revision:  http://reviews.llvm.org/D8491	

llvm-svn: 232926
diff --git a/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp b/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp
index ba0bbfd..6ae03bf 100644
--- a/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp
+++ b/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp
@@ -964,7 +964,7 @@
     lldb_utility::PseudoTerminal terminal;
     const size_t err_len = 1024;
     char err_str[err_len];
-    lldb::pid_t pid;
+    ::pid_t pid;
 
     // Propagate the environment if one is not supplied.
     if (envp == NULL || envp[0] == NULL)