treewide: more log_*_errno() conversions, multiline calls

Basically:

find . -name '*.[ch]' | while read f; do perl -i.mmm -e \
'local $/;
 local $_=<>;
 s/log_(debug|info|notice|warning|error|emergency)\("([^"]*)%s"([^;]*),\s*strerror\(-?([->a-zA-Z_]+)\)\);/log_\1_errno(\4, "\2%m"\3);/gms;print;' \
 $f; done

Plus manual indentation fixups.

src/core/loopback-setup.c

@@ -93,13 +93,11 @@ int loopback_setup(void) {
         r = start_loopback(rtnl);
         if (r == -EPERM) {
                 if (check_loopback() < 0) {
-                        log_warning("Failed to configure loopback device: %s",
-                                    strerror(EPERM));
+                        log_warning_errno(EPERM, "Failed to configure loopback device: %m");
                         return -EPERM;
                 }
         } else if (r < 0) {
-                log_warning("Failed to configure loopback device: %s",
-                            strerror(-r));
+                log_warning_errno(r, "Failed to configure loopback device: %m");
                 return r;
         }