Remove old ifdef'ed out checksum code

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
diff --git a/amiga-nvram.c b/amiga-nvram.c
index b974055..3358b82 100644
--- a/amiga-nvram.c
+++ b/amiga-nvram.c
@@ -156,16 +156,9 @@
 
 static uint8_t checksum_nibble(uint8_t sum, uint8_t nibble)
 {
-#if 0
-	nibble = sum ^ (nibble << 4);
-	nibble = (nibble >> 4) | (nibble << 4);
-	sum = (nibble & 0xf0) ^ table[nibble & 0x0f];
-	return sum;
-#else
 	uint8_t index = (sum >> 4) ^ nibble;
 	sum = (sum << 4) ^ table[index];
 	return sum;
-#endif
 }
 
 static uint8_t nvram_checksum(void)