[S390] mark disabled_wait as noreturn function

disabled_wait() won't return, so add an __attribute__((noreturn)).
This will remove a false positive finding which our internal code
checker reports.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/processor.h

@@ -13,6 +13,7 @@
 #ifndef __ASM_S390_PROCESSOR_H
 #define __ASM_S390_PROCESSOR_H
 
+#include <linux/linkage.h>
 #include <asm/ptrace.h>
 
 #ifdef __KERNEL__
@@ -258,7 +259,7 @@ static inline void enabled_wait(void)
  * Function to drop a processor into disabled wait state
  */
 
-static inline void disabled_wait(unsigned long code)
+static inline void ATTRIB_NORET disabled_wait(unsigned long code)
 {
         unsigned long ctl_buf;
         psw_t dw_psw;
@@ -322,6 +323,7 @@ static inline void disabled_wait(unsigned long code)
 		: "=m" (ctl_buf)
 		: "a" (&dw_psw), "a" (&ctl_buf), "m" (dw_psw) : "cc", "0");
 #endif /* __s390x__ */
+	while (1);
 }
 
 /*