sd-device: remove debug log message when dirs are missing

This is a common case, and nothing noteworthy at all. For example, if we
establish an enumerator for listing all devices tagged by some tag, then
the per-tag dir is not going to exist if there are currently no devices
tagged that way, but that's a really common case, and doesn't really
deserve any mention, not even at debug level.

(cherry picked from commit a68c97a54527cacaeeac0c117493639fc455ef5e)
(cherry picked from commit 8aa9e60f89f84a90fb364ee66cf62432a6b877ba)

src/libsystemd/sd-device/device-enumerator.c

@@ -707,13 +707,11 @@ static int enumerator_scan_dir_and_add_devices(
 
         dir = opendir(path);
         if (!dir) {
-                bool ignore = errno == ENOENT;
+                /* This is necessarily racey, so ignore missing directories */
+                if (errno == ENOENT)
+                        return 0;
 
-                /* this is necessarily racey, so ignore missing directories */
-                log_debug_errno(errno,
-                                "sd-device-enumerator: Failed to open directory %s%s: %m",
-                                path, ignore ? ", ignoring" : "");
-                return ignore ? 0 : -errno;
+                return log_debug_errno(errno, "sd-device-enumerator: Failed to open directory '%s': %m", path);
         }
 
         FOREACH_DIRENT_ALL(de, dir, return -errno) {
@@ -773,12 +771,10 @@ static int enumerator_scan_dir(
 
         dir = opendir(path);
         if (!dir) {
-                bool ignore = errno == ENOENT;
+                if (errno == ENOENT)
+                        return 0;
 
-                log_debug_errno(errno,
-                                "sd-device-enumerator: Failed to open directory %s%s: %m",
-                                path, ignore ? ", ignoring" : "");
-                return ignore ? 0 : -errno;
+                return log_debug_errno(errno, "sd-device-enumerator: Failed to open directory '%s': %m", path);
         }
 
         FOREACH_DIRENT_ALL(de, dir, return -errno) {
@@ -810,12 +806,10 @@ static int enumerator_scan_devices_tag(sd_device_enumerator *enumerator, const c
 
         dir = opendir(path);
         if (!dir) {
-                bool ignore = errno == ENOENT;
+                if (errno == ENOENT)
+                        return 0;
 
-                log_debug_errno(errno,
-                                "sd-device-enumerator: Failed to open directory %s%s: %m",
-                                path, ignore ? ", ignoring" : "");
-                return ignore ? 0 : -errno;
+                return log_debug_errno(errno, "sd-device-enumerator: Failed to open directory '%s': %m", path);
         }
 
         /* TODO: filter away subsystems? */
@@ -898,12 +892,10 @@ static int parent_crawl_children(sd_device_enumerator *enumerator, const char *p
 
         dir = opendir(path);
         if (!dir) {
-                bool ignore = errno == ENOENT;
+                if (errno == ENOENT)
+                        return 0;
 
-                log_debug_errno(errno,
-                                "sd-device-enumerator: Failed to open directory %s%s: %m",
-                                path, ignore ? ", ignoring" : "");
-                return ignore ? 0 : -errno;
+                return log_debug_errno(errno, "sd-device-enumerator: Failed to open directory '%s': %m", path);
         }
 
         FOREACH_DIRENT_ALL(de, dir, return -errno) {