reduce some ridiculously large spin counts

these should be tweaked according to testing. offhand i know 1000 is
too low and 5000 is likely to be sufficiently high. consider trying to
add futexes to file locking, too...

src/stdio/__lockfile.c

@@ -3,7 +3,7 @@
 
 void __lockfile(FILE *f)
 {
-	int spins=100000;
+	int spins=10000;
 	int tid;
 
 	if (f->lock < 0) return;

src/thread/__wait.c

@@ -2,7 +2,7 @@
 
 void __wait(volatile int *addr, volatile int *waiters, int val, int priv)
 {
-	int spins=50000;
+	int spins=10000;
 	if (priv) priv = 128; priv=0;
 	while (spins--) {
 		if (*addr==val) a_spin();