Spelling correction

src/core/iomgr/pollset_posix.c

@@ -106,7 +106,7 @@ void grpc_pollset_init(grpc_pollset *pollset) {
 void grpc_pollset_add_fd(grpc_pollset *pollset, grpc_fd *fd) {
   gpr_mu_lock(&pollset->mu);
   pollset->vtable->add_fd(pollset, fd, 1);
-  /* the following (enabled only in debug) will reacquire and then releast
+  /* the following (enabled only in debug) will reacquire and then release
      our lock - meaning that if the unlocking flag passed to del_fd above is
      not respected, the code will deadlock (in a way that we have a chance of
      debugging) */
@@ -119,7 +119,7 @@ void grpc_pollset_add_fd(grpc_pollset *pollset, grpc_fd *fd) {
 void grpc_pollset_del_fd(grpc_pollset *pollset, grpc_fd *fd) {
   gpr_mu_lock(&pollset->mu);
   pollset->vtable->del_fd(pollset, fd, 1);
-  /* the following (enabled only in debug) will reacquire and then releast
+  /* the following (enabled only in debug) will reacquire and then release
      our lock - meaning that if the unlocking flag passed to del_fd above is
      not respected, the code will deadlock (in a way that we have a chance of
      debugging) */