Remove the return type from the syscall lists and parser.

It's not used, so it's just noise.

Change-Id: I58260bf3f2f8513f80dc9fa59e856e4d23e4a011
diff --git a/libc/SECCOMP_ALLOWLIST_SYSTEM.TXT b/libc/SECCOMP_ALLOWLIST_SYSTEM.TXT
index 756affe..ac90aac 100644
--- a/libc/SECCOMP_ALLOWLIST_SYSTEM.TXT
+++ b/libc/SECCOMP_ALLOWLIST_SYSTEM.TXT
@@ -3,4 +3,4 @@
 #
 # This file is processed by a python script named genseccomp.py.
 
-int bpf(int cmd, union bpf_attr *attr, unsigned int size) all
+bpf(int cmd, union bpf_attr *attr, unsigned int size) all