Improved reproting of kernel return codes.

Improved reproting of kernel return codes.

Reviewed by Anders Carlsson.

* Platform/CoreIPC/mac/ConnectionMac.cpp:
(CoreIPC::Connection::exceptionSourceEventHandler): Added the error string to the log message.
* Platform/mac/SharedMemoryMac.cpp:
(WebKit::SharedMemory::create): Ditto.
* PluginProcess/mac/PluginProcessMainMac.mm:
(WebKit::PluginProcessMain): Ditto. Also changed to log to stderr.
* WebProcess/mac/WebProcessMainMac.mm:
(WebKit::WebProcessMain): Ditto.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@103879 268f45cc-cd09-0410-ab3c-d52691b4dbfc