[PATCH] target/ppc/excp_helper: Add a missing break for POWERPC_EXCP_HISI

[Chen Qun]

When using -Wimplicit-fallthrough in our CFLAGS, the compiler showed warning:
../target/ppc/excp_helper.c: In function ‘powerpc_excp’:
../target/ppc/excp_helper.c:529:13: warning: this statement may fall through 
[-Wimplicit-fallthrough=]
  529 |         msr |= env->error_code;
      |         ~~~~^~~~~~~~~~~~~~~~~~
../target/ppc/excp_helper.c:530:5: note: here
  530 |     case POWERPC_EXCP_HDECR:     /* Hypervisor decrementer exception    
     */
      |     ^~~~

A break statement may be required to enter this exception.

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>

---
I guess there's a break missing in 'POWERPC_EXCP_HISI' branch,
just like the 'POWERPC_EXCP_ISI' branch.
---
 target/ppc/excp_helper.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
index a988ba15f4..5e69ac1b33 100644
--- a/target/ppc/excp_helper.c
+++ b/target/ppc/excp_helper.c
@@ -527,6 +527,7 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int 
excp_model, int excp)
         break;
     case POWERPC_EXCP_HISI:      /* Hypervisor instruction storage exception */
         msr |= env->error_code;
+        break;
     case POWERPC_EXCP_HDECR:     /* Hypervisor decrementer exception         */
     case POWERPC_EXCP_HDSI:      /* Hypervisor data storage exception        */
     case POWERPC_EXCP_HDSEG:     /* Hypervisor data segment exception        */
-- 
2.27.0