user-util: export is_nologin_shell() so that we can use it elsewhere

src/basic/user-util.c

@@ -84,7 +84,7 @@ char *getusername_malloc(void) {
         return uid_to_name(getuid());
 }
 
-static bool is_nologin_shell(const char *shell) {
+bool is_nologin_shell(const char *shell) {
 
         return PATH_IN_SET(shell,
                            /* 'nologin' is the friendliest way to disable logins for a user account. It prints a nice

src/basic/user-util.h

@@ -127,3 +127,5 @@ int putsgent_sane(const struct sgrp *sg, FILE *stream);
 #endif
 
 int make_salt(char **ret);
+
+bool is_nologin_shell(const char *shell);