vgasrc: Don't use VAR16 in header files to fix gcc warning

Some versions of gcc complain when VAR16 is used in both the header
and C files - use only in the C file to fix the warning.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
diff --git a/vgasrc/svgamodes.h b/vgasrc/svgamodes.h
index 782d30b..6ac1d64 100644
--- a/vgasrc/svgamodes.h
+++ b/vgasrc/svgamodes.h
@@ -6,7 +6,7 @@
     struct vgamode_s info;
 };
 
-extern struct generic_svga_mode svga_modes[] VAR16;
-extern unsigned int svga_mcount VAR16;
+extern struct generic_svga_mode svga_modes[];
+extern unsigned int svga_mcount;
 
 #endif /* __SVGAMODES_H */