[PATCH] arm/translate-a64: fix uninitialized variable warning

[pannengyuan]

From: Pan Nengyuan <pannengy...@huawei.com>

Fixes:
target/arm/translate-a64.c: In function 'disas_crypto_three_reg_sha512':
target/arm/translate-a64.c:13625:9: error: 'genfn' may be used uninitialized in 
this function [-Werror=maybe-uninitialized]
    genfn(tcg_rd_ptr, tcg_rn_ptr, tcg_rm_ptr);
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
qemu/target/arm/translate-a64.c:13609:8: error: 'feature' may be used 
uninitialized in this function [-Werror=maybe-uninitialized]
    if (!feature) {

Reported-by: Euler Robot <euler.ro...@huawei.com>
Signed-off-by: Pan Nengyuan <pannengy...@huawei.com>
Cc: Peter Maydell <peter.mayd...@linaro.org> 
---
 target/arm/translate-a64.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index d4bebbe629..211e3d813f 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -13564,8 +13564,8 @@ static void disas_crypto_three_reg_sha512(DisasContext 
*s, uint32_t insn)
     int rm = extract32(insn, 16, 5);
     int rn = extract32(insn, 5, 5);
     int rd = extract32(insn, 0, 5);
-    bool feature;
-    CryptoThreeOpFn *genfn;
+    bool feature = false;
+    CryptoThreeOpFn *genfn = NULL;
 
     if (o == 0) {
         switch (opcode) {
-- 
2.21.0.windows.1