util/grub-gen-asciih.c: fix build warning->error

A potential problem is flagged by the compiler and generates a warning. This
warning is promoted to an error via -Werror. This patch fixes the original
issue, avoids the warning, and therefore avoids the build error.

Upstream-Status: Pending

Index: git/util/grub-gen-asciih.c
===================================================================
--- git.orig/util/grub-gen-asciih.c
+++ git/util/grub-gen-asciih.c
@@ -131,6 +131,8 @@ write_font_ascii_bitmap (FILE *file, FT_
   struct grub_glyph_info glyph;
   int char_code;
 
+  memset (&glyph, 0, sizeof(glyph));
+
   fprintf (file, "/* THIS CHUNK OF BYTES IS AUTOMATICALLY GENERATED */\n");
   fprintf (file, "unsigned char ascii_bitmaps[] =\n");
   fprintf (file, "{\n");
@@ -144,6 +146,12 @@ write_font_ascii_bitmap (FILE *file, FT_
 	return;
       add_glyph (glyph_idx, face, char_code, &glyph);
 
+      if (glyph.bitmap == 0)
+        {
+          fprintf (stderr, "grub-gen-asciih: add_glyph not successful");
+          exit (1);
+        }
+
       if (glyph.width == 8 && glyph.height == 16
 	  && glyph.x_ofs == 0 && glyph.y_ofs == 0)
 	{