[PATCH 13/21] powerpc: Add missing prototype for arch_dup_task_struct

In commit 55ccf3fe3f9a ("fork: move the real prepare_to_copy() users to
arch_dup_task_struct()") a new arch_dup_task_struct was added without a
prototype declared in thread_info.h header. Fix the following warning
(treated as error in W=1):

  CC      arch/powerpc/kernel/process.o
arch/powerpc/kernel/process.c:1609:5: error: no previous prototype for ‘arch_dup_task_struct’ [-Werror=missing-prototypes]
 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
     ^~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors

Signed-off-by: Mathieu Malaterre <redacted>
---
 arch/powerpc/include/asm/thread_info.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 4a12c00f8de3..5964145db03d 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h

@@ -70,6 +70,7 @@ static inline struct thread_info *current_thread_info(void)
 	return (struct thread_info *)val;
 }
 
+extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 #endif /* __ASSEMBLY__ */
 
 /*

-- 
2.11.0