arm64: fix build error in sigcontext.h

I'm seeing this build failure for arm64:

CC [M] Documentation/filesystems/configfs/configfs_example_macros.o
In file included from /usr/include/bits/sigcontext.h:27:0,
from /usr/include/signal.h:340,
from /usr/include/sys/wait.h:30,
from Documentation/accounting/getdelays.c:24:
.../linux/usr/include/asm/sigcontext.h:61:2: error: unknown type name ‘u64’
u64 esr;
^
make[2]: *** [Documentation/accounting/getdelays] Error 1

This was introduced by commit 15af1942dd61ee23:

arm64: Expose ESR_EL1 information to user when SIGSEGV/SIGBUS

Using __u64 instead of u64 fixes the problem.

Signed-off-by: Mark Salter <[e-mail]>
Signed-off-by: Catalin Marinas <[e-mail]>

arch/arm64/include/uapi/asm/sigcontext.h

···
 
 struct esr_context {
 	struct _aarch64_ctx head;
-	u64 esr;
+	__u64 esr;
 };
 
 #endif /* _UAPI__ASM_SIGCONTEXT_H */