copy: move sync_rights() to copy.c and rename copy_rights()

It's so similar to copy_access(), hence let's move it over and rename it
in similar style to the rest of the functions.

No change in behaviour, just moving things over.

src/basic/copy.c

@@ -1232,6 +1232,8 @@ int copy_access(int fdf, int fdt) {
         assert(fdf >= 0);
         assert(fdt >= 0);
 
+        /* Copies just the access mode (and not the ownership) from fdf to fdt */
+
         if (fstat(fdf, &st) < 0)
                 return -errno;
 
@@ -1241,6 +1243,20 @@ int copy_access(int fdf, int fdt) {
         return 0;
 }
 
+int copy_rights(int fdf, int fdt) {
+        struct stat st;
+
+        assert(fdf >= 0);
+        assert(fdt >= 0);
+
+        /* Copies both access mode and ownership from fdf to fdt */
+
+        if (fstat(fdf, &st) < 0)
+                return -errno;
+
+        return fchmod_and_chown(fdt, st.st_mode & 07777, st.st_uid, st.st_gid);
+}
+
 int copy_xattr(int fdf, int fdt) {
         _cleanup_free_ char *names = NULL;
         int ret = 0, r;

src/basic/copy.h

@@ -64,4 +64,5 @@ static inline int copy_bytes(int fdf, int fdt, uint64_t max_bytes, CopyFlags cop
 
 int copy_times(int fdf, int fdt, CopyFlags flags);
 int copy_access(int fdf, int fdt);
+int copy_rights(int fdf, int fdt);
 int copy_xattr(int fdf, int fdt);

src/basic/fileio.c

@@ -1327,15 +1327,6 @@ int warn_file_is_world_accessible(const char *filename, struct stat *st, const c
         return 0;
 }
 
-int sync_rights(int from, int to) {
-        struct stat st;
-
-        if (fstat(from, &st) < 0)
-                return -errno;
-
-        return fchmod_and_chown(to, st.st_mode & 07777, st.st_uid, st.st_gid);
-}
-
 int rename_and_apply_smack_floor_label(const char *from, const char *to) {
         int r = 0;
         if (rename(from, to) < 0)

src/basic/fileio.h

@@ -118,6 +118,4 @@ int safe_fgetc(FILE *f, char *ret);
 
 int warn_file_is_world_accessible(const char *filename, struct stat *st, const char *unit, unsigned line);
 
-int sync_rights(int from, int to);
-
 int rename_and_apply_smack_floor_label(const char *temp_path, const char *dest_path);