Convert ioctl_next_match() to new-style C function definition

* ioctl.c (ioctl_next_match): Convert to new-style C function definition.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
diff --git a/ioctl.c b/ioctl.c
index 153e5df..122f31a 100644
--- a/ioctl.c
+++ b/ioctl.c
@@ -64,8 +64,7 @@
 }
 
 const struct ioctlent *
-ioctl_next_match(iop)
-const struct ioctlent *iop;
+ioctl_next_match(const struct ioctlent *iop)
 {
 	long code;