various: do not include file names directly in error messages

git grep -l 'Failed to open /'|xargs sed -r -i 's|"Failed to open (/[^ ]+): %m"|"Failed to open %s: %m", "\1"|g'
git grep -l $'Failed to open \'/'|xargs sed -r -i $'s|"Failed to open \'(/[^ ]+)\': %m"|"Failed to open %s: %m", "\\1"|g'
git grep -l "Failed to open /"|xargs sed -r -i $'s|"Failed to open (/[^ ]+), ignoring: %m"|"Failed to open %s, ignoring: %m", "\\1"|g'
+ some manual fixups.

src/shared/condition.c

@@ -519,7 +519,7 @@ static int condition_test_firmware_devicetree_compatible(const char *dtcarg) {
         if (r < 0) {
                 /* if the path doesn't exist it is incompatible */
                 if (r != -ENOENT)
-                        log_debug_errno(r, "Failed to open() '%s', assuming machine is incompatible: %m", DTCOMPAT_FILE);
+                        log_debug_errno(r, "Failed to open '%s', assuming machine is incompatible: %m", DTCOMPAT_FILE);
                 return false;
         }