rename check_superuser() to check_privileges()

It's a preparatory commit to reflect upcoming changes in how
capabilities are checked under Linux in presence of libcap-ng.

No functional change.

Signed-off-by: Oleksandr Natalenko <oleksandr@redhat.com>

src/common.c

@@ -103,7 +103,7 @@ int setgroups(int count, int *groups)
 
 #ifndef WINDOWS32
 void
-check_superuser(void)
+check_privileges(void)
 {
 	if (geteuid() != 0) {
 		warnx("Run as root and you'll be happy.");

src/common.h

@@ -105,11 +105,11 @@ enum connection {
 };
 
 #ifdef WINDOWS32
-static inline void check_superuser(void)
+static inline void check_privileges(void)
 {
 }
 #else
-void check_superuser(void);
+void check_privileges(void);
 #endif
 char *format_addr(struct sockaddr_storage *sockaddr, int sockaddr_len);
 int get_addr(char *, int, int, int, struct sockaddr_storage *);

src/iodine.c

@@ -279,7 +279,7 @@ int main(int argc, char **argv)
 		}
 	}
 
-	check_superuser();
+	check_privileges();
 
 	argc -= optind;
 	argv += optind;

src/iodined.c

@@ -2519,7 +2519,7 @@ main(int argc, char **argv)
 	argc -= optind;
 	argv += optind;
 
-	check_superuser();
+	check_privileges();
 
 	if (argc != 2)
 		usage();