raise: Send signal to current thread

Change-Id: Ie4318b8ddd01cc2f58f5e07c1d71376953943153
diff --git a/libc/unistd/raise.c b/libc/unistd/raise.c
index de099da..7b03a7a 100644
--- a/libc/unistd/raise.c
+++ b/libc/unistd/raise.c
@@ -30,5 +30,5 @@
 
 int raise(int signum)
 {
-    return kill(getpid(), signum);
+    return kill(gettid(), signum);
 }