hw/display/exynos4210_fimd: Fix bit-swapping code

fimd_swap_data() includes code to reverse the bits in a
64-bit integer, but an off-by-one error meant that it would
try to shift off the top of the integer. Correct the bug
(spotted by Coverity).
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 1432912615-23107-1-git-send-email-peter.maydell@linaro.org

hw/display/exynos4210_fimd.c

@@ -337,7 +337,7 @@ static inline void fimd_swap_data(unsigned int swap_ctl, uint64_t *data)
     if (swap_ctl & FIMD_WINCON_SWAP_BITS) {
         res = 0;
         for (i = 0; i < 64; i++) {
-            if (x & (1ULL << (64 - i))) {
+            if (x & (1ULL << (63 - i))) {
                 res |= (1ULL << i);
             }
         }