[PATCH] winebuild: Use asm_name for __wine_syscall.

[Jacek Caban]

Signed-off-by: Jacek Caban <jacek(a)codeweavers.com>
---
Fixes compilation with llvm-mingw. function_declaration adds leading 
underscore to the symbol name and lld can't find the symbol if it 
doesn't match.

  tools/winebuild/import.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)