fix __syscall declaration with wrong visibility in syscall_arch.h

remove __syscall declaration where it is not needed (aarch64, arm,
microblaze, or1k) and add the hidden attribute where it is (mips).

arch/aarch64/syscall_arch.h

@@ -3,8 +3,6 @@
 ((union { long long ll; long l[2]; }){ .ll = x }).l[1]
 #define __SYSCALL_LL_O(x) 0, __SYSCALL_LL_E((x))
 
-long (__syscall)(long, ...);
-
 #define __asm_syscall(...) do { \
 	__asm__ __volatile__ ( "svc 0" \
 	: "=r"(x0) : __VA_ARGS__ : "memory", "cc"); \

arch/arm/syscall_arch.h

@@ -3,8 +3,6 @@
 ((union { long long ll; long l[2]; }){ .ll = x }).l[1]
 #define __SYSCALL_LL_O(x) 0, __SYSCALL_LL_E((x))
 
-long (__syscall)(long, ...);
-
 #define __asm_syscall(...) do { \
 	__asm__ __volatile__ ( "svc 0" \
 	: "=r"(r0) : __VA_ARGS__ : "memory"); \

arch/microblaze/syscall_arch.h

@@ -3,8 +3,6 @@
 ((union { long long ll; long l[2]; }){ .ll = x }).l[1]
 #define __SYSCALL_LL_O(x) 0, __SYSCALL_LL_E((x))
 
-long (__syscall)(long, ...);
-
 #ifndef __clang__
 
 static __inline long __syscall0(long n)

arch/mips/syscall_arch.h

@@ -3,6 +3,9 @@
 ((union { long long ll; long l[2]; }){ .ll = x }).l[1]
 #define __SYSCALL_LL_O(x) 0, __SYSCALL_LL_E((x))
 
+#ifdef SHARED
+__attribute__((visibility("hidden")))
+#endif
 long (__syscall)(long, ...);
 
 #define SYSCALL_RLIM_INFINITY (-1UL/2)

arch/or1k/syscall_arch.h

@@ -5,8 +5,6 @@
 
 #define SYSCALL_MMAP2_UNIT 8192ULL
 
-long (__syscall)(long, ...);
-
 #ifndef __clang__
 
 static __inline long __syscall0(long n)