basic/pager: convert the pager options to a flags argument

Pretty much everything uses just the first argument, and this doesn't make this
common pattern more complicated, but makes it simpler to pass multiple options.

src/basic/pager.c

@@ -41,13 +41,13 @@ _noreturn_ static void pager_fallback(void) {
         _exit(EXIT_SUCCESS);
 }
 
-int pager_open(bool no_pager, bool jump_to_end) {
+int pager_open(PagerFlags flags) {
         _cleanup_close_pair_ int fd[2] = { -1, -1 };
         _cleanup_strv_free_ char **pager_args = NULL;
         const char *pager;
         int r;
 
-        if (no_pager)
+        if (flags & PAGER_DISABLE)
                 return 0;
 
         if (pager_pid > 0)
@@ -96,7 +96,7 @@ int pager_open(bool no_pager, bool jump_to_end) {
                 less_opts = getenv("SYSTEMD_LESS");
                 if (!less_opts)
                         less_opts = "FRSXMK";
-                if (jump_to_end)
+                if (flags & PAGER_JUMP_TO_END)
                         less_opts = strjoina(less_opts, " +G");
                 if (setenv("LESS", less_opts, 1) < 0)
                         _exit(EXIT_FAILURE);

src/basic/pager.h

@@ -5,7 +5,12 @@
 
 #include "macro.h"
 
-int pager_open(bool no_pager, bool jump_to_end);
+typedef enum PagerFlags {
+        PAGER_DISABLE     = 1 << 0,
+        PAGER_JUMP_TO_END = 1 << 1,
+} PagerFlags;
+
+int pager_open(PagerFlags flags);
 void pager_close(void);
 bool pager_have(void) _pure_;