pthread: timespec.tv_nsec must be less then 1000000000 ns

src/thread/pthread/SDL_syscond.c

diff --git a/src/thread/pthread/SDL_syscond.c b/src/thread/pthread/SDL_syscond.c
index a1a2e63..c7583dc 100644
--- a/src/thread/pthread/SDL_syscond.c
+++ b/src/thread/pthread/SDL_syscond.c
@@ -114,7 +114,7 @@
     abstime.tv_sec = delta.tv_sec + (ms / 1000);
     abstime.tv_nsec = (long)(delta.tv_usec + (ms % 1000) * 1000) * 1000;
 #endif
-    if (abstime.tv_nsec > 1000000000) {
+    if (abstime.tv_nsec >= 1000000000) {
         abstime.tv_sec += 1;
         abstime.tv_nsec -= 1000000000;
     }

src/thread/pthread/SDL_syssem.c

diff --git a/src/thread/pthread/SDL_syssem.c b/src/thread/pthread/SDL_syssem.c
index 6d0cdd5..9894bab 100644
--- a/src/thread/pthread/SDL_syssem.c
+++ b/src/thread/pthread/SDL_syssem.c
@@ -141,7 +141,7 @@
 #endif
 
     /* Wrap the second if needed */
-    if (ts_timeout.tv_nsec > 1000000000) {
+    if (ts_timeout.tv_nsec >= 1000000000) {
         ts_timeout.tv_sec += 1;
         ts_timeout.tv_nsec -= 1000000000;
     }