syscalls.h: add forward declarations for inplace syscall wrappers

Unclutter -Wmissing-prototypes warning types (enabled at make W=1)

    linux/include/linux/syscalls.h:190:18: warning: no previous prototype for 'SyS_semctl' [-Wmissing-prototypes]
      asmlinkage long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
                      ^
    linux/include/linux/syscalls.h:183:2: note: in expansion of macro '__SYSCALL_DEFINEx'
      __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
      ^
by adding forward declarations right before definitions.
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/compat.h

@@ -43,6 +43,7 @@
 #define COMPAT_SYSCALL_DEFINEx(x, name, ...)				\
 	asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
 	static inline long C_SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
+	asmlinkage long compat_SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__));\
 	asmlinkage long compat_SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__))\
 	{								\
 		return C_SYSC##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__));	\

include/linux/syscalls.h

@@ -186,6 +186,7 @@ extern struct trace_event_functions exit_syscall_print_funcs;
 #define __SYSCALL_DEFINEx(x, name, ...)					\
 	asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));	\
 	static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__));	\
+	asmlinkage long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__));	\
 	asmlinkage long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__))	\
 	{								\
 		long ret = SYSC##name(__MAP(x,__SC_CAST,__VA_ARGS__));	\