libcom_err: declare com_err_gettext to be static

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/lib/et/error_message.c b/lib/et/error_message.c
index dc17984..dc77b69 100644
--- a/lib/et/error_message.c
+++ b/lib/et/error_message.c
@@ -100,7 +100,7 @@
 
 typedef char *(*gettextf) (const char *);
 
-gettextf com_err_gettext = NULL;
+static gettextf com_err_gettext = NULL;
 
 gettextf set_com_err_gettext (new_proc)
     gettextf new_proc;