Rename "system-options" to "systemd-efi-options"

This makes the naming more consistent: we now have
bootctl systemd-efi-options,
$SYSTEMD_EFI_OPTIONS
and the SystemdOptions EFI variable.

(SystemdEFIOptions would be redundant, because it is only used in the context
of efivars, and users don't interact with that name directly.)

bootctl is adjusted to use 2sp indentation, similarly to systemctl and other
programs.

Remove the prefix with the old name from 'bootctl systemd-efi-options' output,
since it's redundant and we don't want the old name anyway.

src/basic/efivars.c

@@ -220,7 +220,7 @@ int efi_set_variable_string(sd_id128_t vendor, const char *name, const char *v)
         return efi_set_variable(vendor, name, u16, (char16_strlen(u16) + 1) * sizeof(char16_t));
 }
 
-int efi_systemd_options_variable(char **line) {
+int systemd_efi_options_variable(char **line) {
         const char *e;
         int r;
 

src/basic/efivars.h

@@ -28,7 +28,7 @@ int efi_get_variable_string(sd_id128_t vendor, const char *name, char **p);
 int efi_set_variable(sd_id128_t vendor, const char *name, const void *value, size_t size);
 int efi_set_variable_string(sd_id128_t vendor, const char *name, const char *p);
 
-int efi_systemd_options_variable(char **line);
+int systemd_efi_options_variable(char **line);
 
 #else
 
@@ -52,7 +52,7 @@ static inline int efi_set_variable_string(sd_id128_t vendor, const char *name, c
         return -EOPNOTSUPP;
 }
 
-static inline int efi_systemd_options_variable(char **line) {
+static inline int systemd_efi_options_variable(char **line) {
         return -ENODATA;
 }
 

src/basic/proc-cmdline.c

@@ -119,7 +119,7 @@ int proc_cmdline_parse(proc_cmdline_parse_t parse_item, void *data, ProcCmdlineF
 
         /* We parse the EFI variable first, because later settings have higher priority. */
 
-        r = efi_systemd_options_variable(&line);
+        r = systemd_efi_options_variable(&line);
         if (r < 0 && r != -ENODATA)
                 log_debug_errno(r, "Failed to get SystemdOptions EFI variable, ignoring: %m");
 
@@ -250,7 +250,7 @@ int proc_cmdline_get_key(const char *key, ProcCmdlineFlags flags, char **ret_val
                 return r;
 
         line = mfree(line);
-        r = efi_systemd_options_variable(&line);
+        r = systemd_efi_options_variable(&line);
         if (r == -ENODATA)
                 return false; /* Not found */
         if (r < 0)