tree-wide: drop spurious newlines (#8764)

Double newlines (i.e. one empty lines) are great to structure code. But
let's avoid triple newlines (i.e. two empty lines), quadruple newlines,
quintuple newlines, …, that's just spurious whitespace.

It's an easy way to drop 121 lines of code, and keeps the coding style
of our sources a bit tigther.

src/shared/bus-unit-util.c

@@ -1098,7 +1098,6 @@ static int bus_append_execute_property(sd_bus_message *m, const char *field, con
                         } else
                                 d = s;
 
-
                         r = sd_bus_message_append(m, "(ssbt)", s, d, ignore_enoent, flags);
                         if (r < 0)
                                 return bus_log_create_error(r);

src/shared/fdset.c

@@ -206,7 +206,6 @@ int fdset_new_listen_fds(FDSet **_s, bool unset) {
         *_s = s;
         return 0;
 
-
 fail:
         if (s)
                 set_free(MAKE_SET(s));

src/shared/firewall-util.c

@@ -168,7 +168,6 @@ int fw_add_local_dnat(
                 uint16_t remote_port,
                 const union in_addr_union *previous_remote) {
 
-
         _cleanup_(iptc_freep) struct xtc_handle *h = NULL;
         struct ipt_entry *entry, *mask;
         struct ipt_entry_target *t;

src/shared/import-util.c

@@ -42,7 +42,6 @@ int import_url_last_component(const char *url, char **ret) {
         return 0;
 }
 
-
 int import_url_change_last_component(const char *url, const char *suffix, char **ret) {
         const char *e;
         char *s;

src/shared/logs-show.c

@@ -52,7 +52,6 @@ static int print_catalog(FILE *f, sd_journal *j) {
         int r;
         _cleanup_free_ char *t = NULL, *z = NULL;
 
-
         r = sd_journal_get_catalog(j, &t);
         if (r < 0)
                 return r;
@@ -84,7 +83,6 @@ static int parse_field(const void *data, size_t length, const char *field, size_
 
         nl = length - field_len;
 
-
         buf = newdup_suffix0(char, (const char*) data + field_len, nl);
         if (!buf)
                 return log_oom();

src/shared/utmp-wtmp.c

@@ -275,7 +275,6 @@ int utmp_put_dead_process(const char *id, pid_t pid, int code, int status) {
         return write_utmp_wtmp(&store, &store_wtmp);
 }
 
-
 int utmp_put_runlevel(int runlevel, int previous) {
         struct utmpx store = {};
         int r;