Added SetLastError() in GetEnvironmentVariableA.

diff --git a/memory/environ.c b/memory/environ.c
index 2b91ac5..7353b95 100644
--- a/memory/environ.c
+++ b/memory/environ.c
@@ -242,7 +242,9 @@
         else if (value) strcpy( value, p );
     }
     LeaveCriticalSection( &current_envdb.section );
-    return ret;  /* FIXME: SetLastError */
+    if (!ret)
+	SetLastError( ERROR_ENVVAR_NOT_FOUND );
+    return ret;
 }