getgrouplist.3, inotify.7: Use sizeof consistently

Use ``sizeof`` consistently through all the examples in the
following way:

- Never use a space after ``sizeof``, and always use parentheses
  around the argument.

  Rationale:
  https://www.kernel.org/doc/html/v5.8/process/coding-style.html#spaces

Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man3/getgrouplist.3

@@ -164,7 +164,7 @@ main(int argc, char *argv[])
 
     ngroups = atoi(argv[2]);
 
-    groups = malloc(ngroups * sizeof (gid_t));
+    groups = malloc(ngroups * sizeof(gid_t));
     if (groups == NULL) {
         perror("malloc");
         exit(EXIT_FAILURE);

man7/inotify.7

@@ -952,7 +952,7 @@ handle_events(int fd, int *wd, int argc, char* argv[])
 
         /* Read some events. */
 
-        len = read(fd, buf, sizeof buf);
+        len = read(fd, buf, sizeof(buf));
         if (len == \-1 && errno != EAGAIN) {
             perror("read");
             exit(EXIT_FAILURE);