[GFS2] Extended attribute code style changes

As per Jan Engelhardt's request and also a few of my own. It has
been possible to add a few most const to the code as a result of
the change in gfs2_ea_name2type.

Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/eaops.h b/fs/gfs2/eaops.h
index b045897..508b4f7 100644
--- a/fs/gfs2/eaops.h
+++ b/fs/gfs2/eaops.h
@@ -20,7 +20,7 @@
 	char *eo_name;
 };
 
-unsigned int gfs2_ea_name2type(const char *name, char **truncated_name);
+unsigned int gfs2_ea_name2type(const char *name, const char **truncated_name);
 
 extern struct gfs2_eattr_operations gfs2_system_eaops;