Use rc_getline instead of assuming a fixed kernel cmdline length.

This is now requires as COMMAND_LINE_SIZE isn't exposed by kernel
headers anymore.
Fixes #177.

src/librc/librc.h

@@ -72,8 +72,6 @@
 #define librc_hidden_proto(x) hidden_proto(x)
 #define librc_hidden_def(x) hidden_def(x)
 
-ssize_t rc_getline(char **, size_t *, FILE *);
-
 librc_hidden_proto(rc_config_list)
 librc_hidden_proto(rc_config_load)
 librc_hidden_proto(rc_config_value)

src/librc/rc.h.in

@@ -517,5 +517,9 @@ typedef LIST_HEAD(rc_pidlist, rc_pid) RC_PIDLIST;
  * @return NULL terminated list of pids */
 RC_PIDLIST *rc_find_pids(const char *, const char *const *, uid_t, pid_t);
 
+/* getline is a handy glibc function that not all libcs have, so
+ * we have our own */
+ssize_t rc_getline(char **, size_t *, FILE *);
+
 __END_DECLS
 #endif

src/librc/rc.map

@@ -12,6 +12,7 @@ global:
 	rc_deptree_update_needed;
 	rc_environ_fd;
 	rc_find_pids;
+	rc_getline;
 	rc_newer_than;
 	rc_older_than;
 	rc_runlevel_exists;