[rhythmbox] fix some constant strings so they're actually constant

[Jonathan Matthew <jmatthew src gnome org>]

commit 40753f9d02d0f3598d0674fedc7b80ae78f6df2b
Author: Jonathan Matthew <jonathan d14n org>
Date:   Sat Jul 15 22:45:11 2017 +1000

    fix some constant strings so they're actually constant
    
    gcc 7 warns about the broken definitions.
    https://bugzilla.gnome.org/show_bug.cgi?id=784957

 lib/rb-text-helpers.c |   10 +++++-----
 widgets/rb-header.c   |    2 +-
 2 files changed, 6 insertions(+), 6 deletions(-)
---
diff --git a/lib/rb-text-helpers.c b/lib/rb-text-helpers.c
index f8cd2ee..2d4472e 100644
--- a/lib/rb-text-helpers.c
+++ b/lib/rb-text-helpers.c
@@ -49,11 +49,11 @@
  *
  * the following constants are in UTF-8 encoding
  */
-static const char const *UNICODE_LRM = "\xE2\x80\x8E";
-static const char const *UNICODE_RLM = "\xE2\x80\x8F";
-static const char const *UNICODE_LRE = "\xE2\x80\xAA";
-static const char const *UNICODE_RLE = "\xE2\x80\xAB";
-static const char const *UNICODE_PDF = "\xE2\x80\xAC";
+static const char *const UNICODE_LRM = "\xE2\x80\x8E";
+static const char *const UNICODE_RLM = "\xE2\x80\x8F";
+static const char *const UNICODE_LRE = "\xE2\x80\xAA";
+static const char *const UNICODE_RLE = "\xE2\x80\xAB";
+static const char *const UNICODE_PDF = "\xE2\x80\xAC";
 
 static void
 append_and_free (GString *str, char *text)
diff --git a/widgets/rb-header.c b/widgets/rb-header.c
index c37a53c..2625849 100644
--- a/widgets/rb-header.c
+++ b/widgets/rb-header.c
@@ -163,7 +163,7 @@ enum
 #define STREAM_FORMAT "%s"
 
 /* unicode graphic characters, encoded in UTF-8 */
-static const char const *UNICODE_MIDDLE_DOT = "\xC2\xB7";
+static const char *const UNICODE_MIDDLE_DOT = "\xC2\xB7";
 
 #define SCROLL_UP_SEEK_OFFSET  5
 #define SCROLL_DOWN_SEEK_OFFSET -5