Implement POSIX pthread_mutex_timedlock.

This replaces the non-standard pthread_mutex_lock_timeout_np, which we have
to keep around on LP32 for binary compatibility.

Change-Id: I098dc7cd38369f0c1bec1fac35687fbd27392e00
diff --git a/libc/bionic/pthread_internals.cpp b/libc/bionic/pthread_internals.cpp
index 09c48dc..d4d6099 100644
--- a/libc/bionic/pthread_internals.cpp
+++ b/libc/bionic/pthread_internals.cpp
@@ -75,7 +75,7 @@
 
 // Initialize 'ts' with the difference between 'abstime' and the current time
 // according to 'clock'. Returns -1 if abstime already expired, or 0 otherwise.
-int __timespec_to_absolute(timespec* ts, const timespec* abstime, clockid_t clock) {
+int __timespec_from_absolute(timespec* ts, const timespec* abstime, clockid_t clock) {
   clock_gettime(clock, ts);
   ts->tv_sec  = abstime->tv_sec - ts->tv_sec;
   ts->tv_nsec = abstime->tv_nsec - ts->tv_nsec;