x86/entry: Remove ABI prefixes from functions in syscall tables

Move the ABI prefixes to the __SYSCALL_[abi]() macros.  This allows removal
of the need to strip the prefix for UML.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200313195144.164260-13-brgerst@gmail.com

arch/x86/entry/syscall_64.c

@@ -11,11 +11,11 @@
 #define __SYSCALL_X32(nr, sym)
 #define __SYSCALL_COMMON(nr, sym) __SYSCALL_64(nr, sym)
 
-#define __SYSCALL_64(nr, sym) extern asmlinkage long sym(const struct pt_regs *);
+#define __SYSCALL_64(nr, sym) extern asmlinkage long __x64_##sym(const struct pt_regs *);
 #include <asm/syscalls_64.h>
 #undef __SYSCALL_64
 
-#define __SYSCALL_64(nr, sym) [nr] = sym,
+#define __SYSCALL_64(nr, sym) [nr] = __x64_##sym,
 
 asmlinkage const sys_call_ptr_t sys_call_table[__NR_syscall_max+1] = {
 	/*