vga.h: Fix prepocessor warning

Mark comment as comment, fixes:
include/asm/vga.h:6:8: warning: extra tokens at end of #endif directive
Signed-off-by: Frank Lichtenheld <frank@lichtenheld.de>
Signed-off-by: Adrian Bunk <bunk@kernel.org>

include/asm-parisc/vga.h

@@ -3,4 +3,4 @@
 
 /* nothing */
 
-#endif __ASM_PARISC_VGA_H__
+#endif /* __ASM_PARISC_VGA_H__ */