um: take register_winch_irq() into the caller of is_skas_winch()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index 30f1bb4..29e4ab7 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -26,11 +26,7 @@
 
 int is_skas_winch(int pid, int fd, void *data)
 {
-	if (pid != getpgrp())
-		return 0;
-
-	register_winch_irq(-1, fd, -1, data, 0);
-	return 1;
+	return pid == getpgrp();
 }
 
 static int ptrace_dump_regs(int pid)