[Linux] Display a warning in AP if inotify fails to initialize

Signed-off-by: Chris Burel <burelc@amazon.com>

Code/Tools/AssetProcessor/Platform/Linux/native/FileWatcher/FileWatcher_linux.cpp

@@ -34,6 +34,12 @@ struct FolderRootWatch::PlatformImplementation
         {
             // The CLOEXEC flag prevents the inotify watchers from copying on fork/exec
             m_iNotifyHandle = inotify_init1(IN_CLOEXEC);
+            const auto err = errno;
+
+            if (m_iNotifyHandle < 0)
+            {
+                AZ_Warning("FileWatcher", false, "Unable to initialize inotify, file monitoring will not be available: %s\n", strerror(err));
+            }
         }
         return (m_iNotifyHandle >= 0);
     }