[cogl] Don't export cogl_gl_error_to_string

[Neil Roberts <nroberts src gnome org>]

commit 2196518b00d7a9f4c5b1eaded44d45ccbdaeaf49
Author: Neil Roberts <neil linux intel com>
Date:   Fri Mar 9 16:40:42 2012 +0000

    Don't export cogl_gl_error_to_string
    
    This is only used internally when debugging is enabled to give a
    human-readable name to a GL error so we shouldn't be exporting it
    outside of the library. This just adds an underscore to the symbol
    name. This shouldn't end up removing any public symbols from the 1.9.8
    release because by default a non-git build disables debug so it wasn't
    exported anyway.
    
    Reviewed-by: Robert Bragg <robert linux intel com>

 cogl/cogl-internal.h |    6 +++---
 cogl/cogl.c          |    2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/cogl/cogl-internal.h b/cogl/cogl-internal.h
index 5c9a097..9019859 100644
--- a/cogl/cogl-internal.h
+++ b/cogl/cogl-internal.h
@@ -33,7 +33,7 @@
 #ifdef COGL_GL_DEBUG
 
 const char *
-cogl_gl_error_to_string (GLenum error_code);
+_cogl_gl_error_to_string (GLenum error_code);
 
 #define GE(ctx, x)                      G_STMT_START {  \
   GLenum __err;                                         \
@@ -43,7 +43,7 @@ cogl_gl_error_to_string (GLenum error_code);
       g_warning ("%s: GL error (%d): %s\n",             \
                  G_STRLOC,                              \
                  __err,                                 \
-                 cogl_gl_error_to_string (__err));      \
+                 _cogl_gl_error_to_string (__err));     \
     }                                   } G_STMT_END
 
 #define GE_RET(ret, ctx, x)             G_STMT_START {  \
@@ -54,7 +54,7 @@ cogl_gl_error_to_string (GLenum error_code);
       g_warning ("%s: GL error (%d): %s\n",             \
                  G_STRLOC,                              \
                  __err,                                 \
-                 cogl_gl_error_to_string (__err));      \
+                 _cogl_gl_error_to_string (__err));     \
     }                                   } G_STMT_END
 
 #else /* !COGL_GL_DEBUG */
diff --git a/cogl/cogl.c b/cogl/cogl.c
index eece03d..8bc48e8 100644
--- a/cogl/cogl.c
+++ b/cogl/cogl.c
@@ -79,7 +79,7 @@ static const struct {
 static const unsigned int n_gl_errors = G_N_ELEMENTS (gl_errors);
 
 const char *
-cogl_gl_error_to_string (GLenum error_code)
+_cogl_gl_error_to_string (GLenum error_code)
 {
   int i;